Draft Survey: Specimen of Calculation

As I have promised you, I write down this post to explain specimen of Calculation in Draft Survey. Please also refer to the previous post Draft Survey : Procedures and Calculation.

Ok, now we could directly go to the point. The vessel has alongside at the wharf in port to discharge the grain cargo. The Ship’s Particulars shown :

Name of Vessel : MV. OCEAN BALL, - Port of Registry (POR) : Panama, – Lenght Over All (LOA) : 182.00 M, – Lenght Between Perpendiculars (LBP) : 179.00 M, – Breath (B) : 32.20 M, – Depth (D) : 17.15 M, – Gross Tonnage (GT) : 28,342 MT, – Net Tonnage (NT) : 17,664 MT, – Summer Draft (SD) : 12.163 M, – Summer Deadweight (DWT) : 52,998 MT, – Light Ship (LS) : 7,780 MT, Constant (CS) : 320 MT, – Fore Distance to Perpendicular (Fd) : 1.70 M, – After Distance to Perpendicular (Ad) : 9.45 M.  See Picture :

foreaftdistance Draft Survey: Specimen of Calculation

The Surveyor came onboard and made Draft Survey to determine the quantity of cargo on arrival. During inspection, she’s draft marks and others data finds as the followings :
- Fore Draft Port (FP) : 10.79 M / Fore Draft Starboard (FS) : 10.81 M.
- Mid Draft Port (MP) : 10.90 M / Mid Draft Starboard (MS) : 11.03 M.
- Aft Draft Port (AP) : 11.16 M / Aft Draft Starboard (AF) : 11.19 M.
- Density of Sea Water Sample (Den) : 1.021.
- Ballast Water (BW) : 265.00 Cubic Meter at Density 1.025, – Fresh Water (FW) : 183.00 MT.
- Fuel Oil (FO) :  612.00 MT, - Diesel Oil (DO) : 161.00 MT, – Lub Oil (LO) : 29.00 MT.
The Draft Survey Calculation is described as below :Raw Draft Calculation
- Fore Mean (Fm) = (FP + FS) / 2 = (10.79 + 10.81) / 2 = 21.60 / 2 = 10.800 M.
- Mid Mean (Mm) = (MP + MS) / 2 = (10.90 + 11.03) / 2 = 21.93 / 2 = 10.965 M.
- Aft Mean (Am) = (AP + AS) / 2 = (11.16 + 10.19) / 2 = 22.35 / 2 = 11.175 M.
- Apparent Trim (AT) = Am – Fm = 11.175 – 10.800 = 0.375 M.
- Length Between Mark (LBM) = LBP – (Fd + Ad) = 179.00 – (1.70 + 9.45)
= 167.85 M

Draft Correction to Distance to Perpendicular.
- Fore Correction (Fc) = (Fd x AT) / LBM = (1.70 x 0.375) / 167.85 = 0.003798
= 0.004 M (rounded to 3 Decimals).
- Mid Correction (Mc) = (Md x AT) / LBM = (0.00 x 0.375) / 167.85
= 0.000 M (Not Available)
- Aft Correction (Ac) = (Ad x AT) / LBM = (9.45 x 0.375) / 167.85 = 0.021112
= 0.021 M (rounded to 3 Decimals).

True Draft and True Trim
- Fore Draft Corrected (Fcd) = Fm + Fc = 10.800 + (-0.004) = 10.796 M.
- Mid Draft Corrected (Mcd) = Mm + Mc = 10.965 + 0.000 = 10.965 M.
- Aft Draft Corrected (Acd) = Am + Ac = 11.175 + 0.021 = 11.196 M.
- True Trim (TT) = Acm – Fcm = 11.196 – 10.796 = 0.400 M.

Final Draft Calculation
- Fore and Aft Mean (FAm) = (Fcd + Acd) / 2 = (10.796 + 11.196) / 2 = 21.992 /2 = 10.996 M.
- Mean of Mean Draft (MM) = (Mcd + FAm / 2) = (10.965 + 10.996) /2 = 21.961 / 2 = 10.9805 M.
- Quarter Mean (MMM) = (MM + Mcd) /2 = (10.9805 + 10.965) /2 = 21.9455 /2 = 10.97275 M.
= 10.973 M.
- Or MMM = {(Fcd x 1) + (Acd x 1) + (Mcd x 6)} / 8 = {(10.796 x 1) + (11.196 x 1) + (10.996 x 6)} / 8
= (10.796 + 11.196 + 65.790) / 8 = 87.782 / 8 = 10.97275 M = 10.973 M.

Hydrostatic Table

Refer to the Table, we could obtain :

Displacement (Disp)
- Disp  at 10.970 M :  54,266.860 MT (DISP. FULL).
- Disp at 10.980 M :  54,321.070 MT (DISP. FULL).
- Disp at 10.973 M : 54,266.860 +[ {(10.973 - 10.970) / (10.980 - 10.970)} x (54,321.070 - 54,266.860)]
= 54,266.860 {(0.003 /0.010) x 54.210} = 54,266.86 + (0.3 x 54.210)
= 54,266.860 + 16.263 = 54,283.123 MT

Ton Per Centimeter (TPC)
- TPC  at 10.970 M :  54.210 MT (Below TPC on Table).
- TPC  at 10.980 M :  54.220 MT (Below TPC on Table).
- TPC at 10.973 M : 54.210 +[ {(10.973 - 10.970) / (10.980 - 10.970)} x (54.220 - 54.210)]
= 54.210 {(0.003 /0.010) x 0.010} = 54.210 + (0.3 x 0.010)
= 54.210 + 0.003 = 54.213 MT.

Longitudinal Centre Flotation (LCF)
- LCF  at 10.970 M :  1.180 MT (Below LCF on Table).
- LCF  at 10.980 M :  1.190 MT (Below LCF on Table).
- LCF at 10.973 M : 1.180 +[ {(10.973 - 10.970) / (10.980 - 10.970)} x (1.190 - 1.180)]
= 1.180 {(0.003 /0.010) x 0.010} = 1.180 + (0.3 x 0.010) = 1.180 + 0.003 = 1.183 M.
 Draft Survey: Specimen of Calculation
Moment To Change Trim (MTC)
- MTC = MTC 1 – MTC 2.
- MTC 1 = MMM + 0.5 = 10.973 + 0.5 = 11.473 M.
- MTC 1  at 11.470 M :  709.910  (Below Table).
- MTC 1 at 11.480 M :  710.060 (Below Table).
- MTC 1 at 11.473 M : 709.910 +[ {(11.473 - 11.470) / (11.480 - 11.470)} x (710.060 - 709.910)]
= 709.910 {(0.003 / 0.010) x 0.150} = 709.910 + (0.3 x 0.450) = 709.610 + 0.045 = 709.955. Draft Survey: Specimen of Calculation
- MTC 2 = MMM - 0.5 = 10.973 - 0.5 = 10.473 M.
- MTC 2  at 10.470 M :  686.460  (Below MTC on Table).
- MTC 2 at 10.480 M :  686.770 (Below MTC on Table).
- MTC 2 at 10.473 M : 686.460 +[ {(10.473 - 10.470) / (10.480 - 10.470)} x (686.770 - 686.460)]
= 686.460 {(0.003 /0.010) x 0.310} = 686.460 + (0.3 x 0.310) = 686.460 + 0.093 = 686.553.
 Draft Survey: Specimen of Calculation
So,  MTC = MTC 1 – MTC 2 = 709.955 – 686.553 = 23.402.
**** From the above results, we collected the data as follows:
- Disp = 54,283.123 MT, - True Trim (TT) = 0.400 M, - LBP = 179.00 M,
- TPC = 54.213, – LCF = 1.183, - MCT = 23.402.

First Trim Correction (FTc)
- FTc = (TT x TPC x LCF x 100) / LBP =  (0.400 x 54.213 x 1.183 x 100) / 179.000
= 256.35916 / 179.00 = 14.331615 = 14.332 MT.

Second Trim Correction (STc)
- STc = (TT x TT x MTC x 50) / LBP = (0.400 x 0.400 x 23.402 x 50) / 179.000
= 185.536 / 179.00 = 1. 045899 = 1.046 MT.

Displacement Corrected to Trim (DispT)
- DispT = Disp + (FTc + STc) = 54,283.123 + (14.332 + 1.046) = 54,283.123 + 15.378
= 54,298.501 MT.

Density Correction (Denc) <
- Actual Density (ADen) = Sample Sea Water Density = 1.021
- Denc = DispT x {(ADen – 1.025) / 1.025} = 54,298.501 x {(1.021 – 1.025) / 1.025}
= 54,298.501 x (-0.004 / 1.025)
= 54,298.501 x  (-0.0039024) = -211.89947 = -211.899 MT.

Displacement Corrected to Density (DispDenc)
- DispDenc = DispT + Denc = 54,298.501 + (-211.899) = 54,086.602 MT.

Deductible Weight (Deduct)
- BW = 265.00 x 1.025 = 271. 625 MT, – FW = 183.000 MT, – FO =  612.000 MT,
- DO = 161.000 MT, – LO = 29.000 MT.
- Total Deduct = 1,256.625 MT.

Displacement Minus to Deductible Weight = Net Displacement (NDisp)
- NDisp = DispDenc - Deduct = 54,086.602 – 1,256.625 = 52,829.977 MT.

Estimated Cargo onboard (EstCOB)
- To estimated quantity cargo onboard, we need to know about Light Ship and Constant. Light Ship and Constant data is provided on the Ship’s Loading Manual. For the new ship, we could refer to the Constant on the Manual, but for the old ship it Constant may vary, please refer to the Chief Officer Constant Declaration or Draft Survey Previous Port, or we could calculate it in the final survey after the Ship completing to discharge her cargoes (empty Ship).
- Light Ship (LS) = 7,780.000 MT, – Constant (CS) = 320.000 MT.
- EstCOB = NDisp – (LS + CS) = 52,829.977 – (7,780.000 + 320.00)
= 52,829.977 – 8,100.000 = 44,729.977 MT.


See the following Draft Survey Report Form..

draft form Draft Survey: Specimen of Calculation














We have completed the Initial Draft Survey, I hope it useful and see you in the next post.


Author: Faisal Yusuf

Hi, my name is Faisal Yusuf, but people can call me Surveyors. I live in Jakarta, Indonesia and work as a surveyor.

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  1. Dear Capt. Ayad,

    This also known as dm/dz or dm~dz.

    Where dm/dz is the rate of change of Mctc per unit of draft
    (1 meter). It is the difference in Mctc for 50 cm above and
    below the mean draft.


  2. MTC1=MMM+0.5
    THIS + 0.5 OR -0.5 FROM WHERE I GET IT.

  3. Dear Avin,

    Thanks you for the question.

    Yes, that is correct. so in the final survey you will get the new quantity loaded only. ROB is not included.
    It is recommended to declare the estimate ROB on board before loading, as the people will know the actual quantity of total cargo on board.


  4. Dear Azim,

    See in previous comment.

    Suggested to use the following:

    - Expect to read the Draft maximum sea vessels, although it is not possible or dangerous.
    - In circumstances like this, read the Draft and land next to the sea with the help of manometer, consisting of clear plastic hose, strong, mounted on both ends of the pipe to facilitate water level measurements.
    - If possible, pipes installed along the width of the entire ship – the size is taken from the overall width.
    - Reading Draft sea side obtained through adding to or subtracting from the land side of the manometer readings
    - The surface is measured from the same base line and taken to the same distance from both sides of the ship’s centerline.
    - All air must be expelled from the hose and the pipe surface is maintained at a higher elevation than the deck on the centerline.
    - The height of the water surface on both sides of the ship measured above deckline (h) or other fixed surface. The difference between the height divided by two and the result (d) is added to or subtracted from the readings Draft one to get the mean on Draft centerline.

    Draft midships left = 8.00M, the right side of the manometer readings 8.50M on both sides of centerline.
    Full width of the ship = 20.85m. Draft midships Calculate the mean, the centerline Draft, if the difference between the 2 readings manometer manometer readings higher right = 25cm.

    - ANSWER: The width of effective 8:50 x 2 = 17.00M, with the triangle at 0:25: 17 = d: 20.85
    d = 20.85×0.25: 17 = 0.307m wide differences in management.
    Differences half-width = 0307: 2 = 0.153m. Centerline Draft = 0153 8:00 = 8.153m

    THE U.K. VERSION, 1994

  5. Dear William,

    Thanks for your comments. I didn’t have it. Suggesting you to make your own questions and answers then giving to the trainee surveyors.


  6. Good Day MR. SURVEYOR

    kindly guide me…. the vsl is a cement carrier and own by the cement company, loadport and disport is own also by the cement company but different surveying comapny… after discharging at loadport we have R.O.B.

    after conducting Initial & Final Draft Survey at loadport, they add the ROB to their final displacement.. is this correct?? also after conducting final draft survey & geting the final displacement, is this the fresh pruoduct or the new product qty on board


  8. Good day Mr Faisal, how to conduct a draft survey on barges. Most barges don’t stated the LBP and distance of draft mark to PP on their hydrostatic tables and so do the MCTC. They only stated the LOA and of course its different from LBP. So to find the corrected draft and corrected displacement due to trim could not be done.
    Is it o.k. only to use the Quater Mean to get the displacement without the correction or is there any other method to find the correction to apply to the displacement without those information.

  9. Faisal good morning,
    Do you have exercises with answer about Draft Survey?
    This is for practices of our surveyors in Panamá.

    thank you for you attention.

    William Pineda

  10. Hi
    I would like to know how to create Trimming table. this table is created by the naval architect and included in the hydrostatic table.
    will any naval architect can explain me how to create this or by any other professionals.
    thanks for your help.

    Paulo Ricardo

  11. Good day Sirs,

    Thank you for the reply, i still don’t know what is the importance of LCF and MTC, i mean, what do they represent with respect to the shape of the vessel?

  12. Dear Jessie,

    Negative constant means the constant of the vessel under zero (0). actually it is impossible to have, but practically we could found some cases.
    in case the negative constant found, means the vessel has modified. after modifying, she does not change the loading manual and/or re-calibrate her hydrostatic table yet.
    in my opinion the effect are :
    - the calculation could not be determined the exact quantity of cargo loaded, it could be less or more.
    - the draft survey result is not recommended for total loaded quantity.

    for LCF you could check at the curve on ship’s loading manual book. but generally for bulk carrier, not all, the small/light draft LCF will show minus and move to the large/load draft LCF with plus.

    The constant is depends on the vessel stuffs/equipment and provision. for instance the smaller cargo ship attached with steel grabs will be heavier than the bigger gear-less cargo ship. as well, the constant is growing gradually based on the ship ages. it could be added by underkeel marine growth, mud on tanks, corrosion, paint and coating, etc.. check also Draft Survey Factor Effecting.


  13. Hello Surveyors,

    I am a process engr and part of my job is to witness draft surveys as company’s rep. We usually handle bulk and liquids. I have a few questions:
    - what is the effect of having a negative (-) constant?
    - how can we determine whether LCF is – or + ?
    - there are instances that heavier ships have smaller constant than lighter ships, it is somewhat ironic. how can we verify that the calculated constant is dependable?

  14. Dear Mr Faysal
    Good days
    Mr Faysal ………….I want to know the rules for calculating the successive bunker survey and petroleum survey

    With my respects to you Mr. Faisal

  15. Peace upon you master Faisal
    I am novice surveyor …..
    Please Syed Faisal …..
    I want an easy way to calculate ………..
    1 stem correction
    2 corrected forw+aft
    3 mean draft fwd&aft
    4 midship correction
    5 corrected midship
    6 mean of mean
    7 correction for deformation
    8 keel correction
    9 displacement
    10 trim carrection (1st and 2nd)
    11displacement corrected for trim
    12 displacement corrected for density……
    I want a simple way to understand…….

    With thanks and gratitude to the esteemed Mr. yourselves
    Best reagards
    Surveyor junior

  16. Advise on draft survey report .

  17. Urgently in need of surveyor in Djibouti to issue Gas Free Certificate for Tank container which is empty.

  18. Hi James,

    There is no issue about this, the freeboard and draftmark are sets to the same result of calculation.

    The dicrepancy could be caused by the accuracy of measuring the freeboard manually, and correctness of freeboard indicator.
    As my experience, it is hard to manually measures the freeboard especially in swell sea condition.
    If you use the freeboard indicator: After using several times, the correction and calibration is needed for any indicator products.


  19. Dear Kouevi

    All sevensurveyor software has no selling price, what you need to do is donating at $10, $20, $30, $40 or $50 on to my paypal account and I will send you the full version.

    Follow this link for donation. Donation here.

    Don’t forget to email me when you have donated. Along with the email, you should complete the brief profile as below references:
    Software Requested:

    I will process your software soon. But please considering and need a little patient, as I am not available at all time (I have company to serve). Keep promise you to get the software ASAP.


  20. Dear Omar,

    The first calculation is pointed to the obtain the displacement on sea water density (1.025). Commonly, the hydostatic table is made base on that density including TPC, LCF, MTC. After we gaining the MMM displacement, the 1st and 2nd corrections should be made at 1.025 as well.

    In my opinion, logically if you want to use dock density “for example 1.021″, you should start from the reading draft. So, you will get the MMM and TPC as per dock water density. But I have never try to calculate this way, as there is no any draft survey guidances or procedures are made base on this.


  21. What is your thoughts on the use of freeboard indicators for establishing the drafts of a vessel? I have found at times this method to be very useful particularly when access to the offshore drafts marks is limited. I have also found this method to have problems particularly when the drafts established by the freeboard indicator is several inches or centimeters different from the observed drafts. Could you comment on this? Thank you.

  22. want the draft survey programm

  23. Hello
    This question is very urgently, I have quastion about tpc, why you don’t correct tpc to dock water density in the example, so you are used the tpc which versus to mmm on table, my knowledge the value of tpc on table according to salt water density 1,025.
    I will be happy if answer and if can u send answer to my Emil many thnx

    Best rgrds

  24. This is amaging site for those who are related with this job.

  25. Dear Eng. Yacout,

    Thanks, I will inform you if any good program for load tanker.


  26. I am junior surveyor struggling to learn draft survey i need to know about correction of draft to keel deflection but i kwon to found the displecement so i don’t kwon calculete TPC , LCF and MTC.
    Best Regards,
    Paulo Ricardo.

  27. Dear Sir
    First, thank you loyal to the explanation of how to calculate the displacement, the quantity of goods loaded into the holds of the ship and when any draft of you easily, where I stopped for a considerable period for the exercise of inspections.
    But life here in Egypt has become difficult and therefore resorted to the practice of examinations again, where I told the seventy-one years old.
    I hope you have a modern program because I work now since 30 years, as well as price, and is there to explain and in the account to load tankers.
    Finally, we thank you for your help I am waiting for reply.

  28. Dear Edgar,

    Thanks, you have a sharp eye, this is very advantage for surveyor. Success for you.


  29. Dear Romy,

    For common vessel draft survey, I do not find the rules as you are explained above.

    But if the stability manual on board is stated it, you should be followed. Because the correct draft calculation of one ship is refers to the manual book available on that ship.


  30. Dear Riad,

    There is no different between initial and final calculation.


  31. Hi Mr. Surveyor!
    I am a Trainee Chief Officer. I really find your blog very helpful. Many thanks for posting this.
    I just found a *typographical error in your calc.
    - Light Ship (LS) = 7,780.000 MT, – Constant (CS) = 320.000 MT.
    - EstCOB = NDisp – (LS + CS) = 52,829.977 – (***7,780.000 + 320.00***)
    = 52,829.977 – ***7,100.000 = 44,729.977 MT

    *** should be 8100 (instead of ***7100). ***7780 + 320*** = 8100
    Just a typo error. Answer is still correct. ***44,729.977.
    Just corrected it for everyone’s info, so that they may not be confused when they follow the Calculations. ;-)
    Again, Many thanks for posting this! Pls continue to educate us beginners.

  32. Dear Surveyor,
    Thank you for your effort in posting a detailed draft survey. I remember when I was still sailing as a Chief Officer, Trim Correction (the 2nd one) will be applied only when the Trin is 1% or more of the LBP( this is according to Stability Manual onboard), This means that if the LBP is 179m and the trim is 0.40m, 2nd correction is not applicable because it did not reach the criteria of 1% of LBP(1% of LBP is 1.79m trim). Please enligthen me regarding this matter.


  33. You have given a complete calculation of draft survey in a very clear and easily understandable manner even to a lay man. It is a wonderful job done.

    Please explain the role of longitudinal center of floatation (LCF), tonne per centimeter (TPC) and moment to change trim (MTC) in the calculation of draft survey of bulk cargo vessels. Also how to correctly assess the weight of deductibles like fuel oil, diesel oil, lubricating oil, ballast water, fresh water etc. in a draft survey.

    Best regards,
    PR Reddi

  34. the final survey mv : MV. OCEAN BALL
    Draft Survey: Specimen of Calculation

  35. Mr.Surveyor
    Good day. I am a junior surveyor
    final survey for MV. OCEAN BALL plz

  36. Dear Bheny,

    Thanks for correction, have just changed the error.


  37. Dear Bheny,

    I have answered some questions about ballast and sounding. You could check some comments in the post of Draft Survey and Bunker Survey.


  38. Thank for knowledge, but please check your MTC 1, I think there is wrongness input number because error in read table

  39. Could you explain about Sounding also, I still confuse about that because there are also correction in there, Could u also explain about that?

  40. dear all,

    I am happy to meet you all.
    I am a practising marine surveyor in Djibouti and I would like to be a part of your exchange network.
    Our company name is Global Maritime Surveyors.

    Thanks in advance

  41. Dear All,

    It is a great pleasure for me to join your website. I am a new marine surveyor since the begining of this year. I started the draft surveys only at the beginning of the year.
    For the moment, I am still practising the draft survey but i still have to learn the bunker survey and liquid surveys. If it is possible i would like to ask you help me on those topics.

    Waberi from Djibouti

  42. Dear George,

    The actual constant will be getting when the ship is empty by Net Displacement – Lightship.
    Net displacement is the displacement after corrected by 1st and 2nd trim correction, density correction, and minus deductible (ballast, freshwater, bunker,etc).

    Example : Net displacement 9,254 MT and lightship 8,888 MT
    CS = 9,254 – 8,888 = 366 MT

    In the initial survey when the vessel carried 50,500 MT cargo (as per B/L), net displacement 59,754 MT and lightship 8,888 MT, you could calculate constant as well, but it is the proximate constant (as we do not know the cargo declare is right or not).
    CS = 59,754 – 50,500 – 8,888 = 366 MT.


  43. Mr.Surveyor could you explain haw to found CONSTANT (CS).and I understood, that it should be found before loading, and till to discharging cargo, it not changeable.
    Pleas, I’ll be very pricier.

  44. Dear Nicolas,

    I think is nothing wrong with your device, except the tiny one. My device was in the same range but it look bigger. It is Germany made and the temperature 27.5 C.

    For temperature 20 C, it is industrial standard. Please check this link: http://pcdmiswiki.org/images/7/7f/NIST_History_of_Thermal_Compensation.pdf.


  45. I ve just got a hydrometer ranging 1.0-1.1, but what confuses me is very small and ranging temperature is 20C.

  46. it s possible the calculate draftsurvey with negative trim

  47. Dear Benny,



  48. Thank you so much for this column!….It is highly appreciated, please oh please never stop this …you information is vital to the assistance of junior surveyours like my self …i look forward to more information about surveying ….it’s such a bonus to my training …thanks again!!!

  49. Dear Capt,

    Up to now, I can’t found another method for 2nd trim corrections as you are requested.


  50. Dear Budi Santoso,

    The Trim is the different between the mean of After Draft and Fore Draft.

    The calculation applied as follows :

    Fore Draft Port side : 2.10 M
    Fore Draft Starboard side : 2.12 M
    Mean of Fore Draft : 2.11 M

    After Draft Port side : 4.34 M
    After Draft Starboard side : 2.36 M
    Mean of After Draft : 4.35 M

    So, the Trim = Mean of After Draft – Mean of Fore Draft = 4.35 M – 2.11 M = 2.24 M.

    Best Regards,

  51. dear sirs: i forget how i can foun 2em trim correction there 2 methode what is the second methode for 2 trim correction
    best regards

  52. I am junior surveyor struggling to learn draft survey . could u explain ”the trim calculation”.

  53. Thanks

  54. Hi Elattar,

    Thanks for appreciation.


  55. Dear Surveyor,

    Thank you very much for the explanation.

    It was brilliant and proves that you have incredible experience

  56. Bro can u explain to me with chart how to get the formula 4 the pependicular correction and trim correction.

  57. hello,
    mean draft = 1.78 meters
    TPC = 10.52 mt
    how do we calculate her draft (in salt water) when she is loaded with 3000 mt of cargo please ?

    thank you.

  58. Hi Vishal,

    Thanks, I will consider it. As now, my job volume is above normal, so I almost have no time to update this blog.

    Best Regards,

  59. Hi, I was going through the draft survey calucation sheet posted by you and it seems to be helpful for bingners… i would appreciate if you can post some litrature on trimming of bulk carriers too… thanks n good day

  60. Dear Tun,

    First, you could do separate the calculation (interpolation) to find the quantity at the trim and sounding easier. See the following steps how to find 2.46 at trim 3.578:

    i. (3.578 – 3.000) : (4.000 – 3.000) = 0.578 : 1.000 = 0.578 = A
    ii. (2.46 – 2.45) : (2.50 -2.45) = 0.01 : 0.05 = 0.20 = B
    iii. 2.45 = 219.8 – {(219.8 – 216.8) x A} = 218.066 = C
    iv. 2.50 = 226.0 – {(226.0 – 223.0) x A} = 224.266 = D
    v. 2.46 = C + {(D – C) x B}

    If you do the right calculation the result should be 219.306.


  61. Dear SIR,


    3.0m 3.578m 4.0m

    2.45 219.8 216.8

    2.46 ????

    2.50 226.0 223.0

  62. Dear Sir,
    I would like to know tank sounding calculation formular.

    sounding 2.46 m and trim 3.578 correction is = 0

    3.0m 3.578m 4.0m
    2.45 219.8 216.8
    2.46 – ??? -
    2.50 226.0 223.0
    So how to gat for value for 2.46 m ,trim 3.578m ???

    Best regards,

  63. Grateful if you could post a Draft Survey Calculation for a vessel with draft marks and hydrostatic tables in Feet & Inches.

  64. Dear Tun,

    Thanks for self-solving your previous two questions.

    As Terms : Ton Per Cm Immersion (TPC) the number of metric tones required to change the mean draft of a vessel by 1 centimeter.
    By means, every centimeter of ship’s draft going up or down on to the water will count by Metric Ton.
    For example : Ship’s Mean Draft is 5.55 M, TPC is 49.00 MT. When the ship’s mean draft is change to 5.56 M, means the ship has received the load quantity 49.00 MT onboard.


  65. Dear Pankaj,

    Thanks for your question. The Ship Beam is the same meaning with Ship Breadth or Ship Width.


  66. DDEAR SIR,



  67. Dear Survyor,

    Sorry sir We have one more question.

    MTC 1 = MMM + 0.5 ( THIS 0.5 IS FROM WHERE,HOW TO GET IT?)



  68. Dear Surveyor,

    Please explain to me above calculation .We do not understand one point TRUE DRAFT AND TRUE TRIM

    HOW GET (Fc is (_ 0.004m) ? From Draft correction to distance to Perpendicular calculation Fc is ( 0.004M)
    Please explaine to me ( _ 0.004m)

    Best regards,

  69. I am junior surveyor struggling to learn draft survey . so please u tell me what is the meaning of ship beam.

  70. Dear John,

    I have explained it on last post “Draft Survey Procedure and Calculation”. Just take a look back.


  71. Good day. I am a junior surveyor struggling to learn draft survey
    I would like to know the formula to calculate especially

    LBM: length between mark
    FD “ Fore distance to perpendicular:
    AD : after distance to perpendicular:
    Thank you very much indeed

  72. Thanks Leyden,

    I will post it once available. Keep in touch,


  73. nice specimen , have any specimens on grain loading calculations . It wud be gr8.

  74. Dear Surveyor,

    Thank you very much for the explanation.

    It was brilliant and proves that you have incredible experience.

    I have used Draft survey Lt which is freely available in google and easily downloadable. Please try it and post your comment on this software.

    Can you please let me know or post a specimen of calculation for
    determining corrected sounding from the one physically observed on the
    tank using a tank capacity table. I have never seen a tank capacity table.

    Best Regards,


  75. Dear Sadanand,

    The VEF is a compilation of the Total Calculated Volume (TCV) measured on the vessel and adjusted for On Board Quantity (OBQ) or ROB (Remaining On Board), and then compared against the shore TCV.

    The adjusted vessel TCV is divided by the shore TCV to obtain a voyage VEF for each voyage. The sum of all the qualifying vessel VEF’s are averaged to obtain the VEF.

    A VEF(L – Load) should be developed at the load port using only load port TCV’s and discharge VEF(D – Discharge)’s should only use discharge port TCV’s. All voyages should be listed starting with the most current and working backwards.

    Even voyages that do not meet the qualifying voyage criteria should be included. A minimum of five qualifying voyages must be used to obtain a workable VEF.

    Voyages prior to structural changes that affected the vessel’s tank capacity should be excluded. Voyages with no shore side measurements should also be excluded along with any voyage that is not with in +/- 0.3% of the average ratio of all voyages listed.

    I have put downloadable pdf file regards to this matter on the download box.

    Source: John A. “Jack” Szallai – Orion Associates L.L.C.

  76. Dear All,

    Please can anyone brief me about V.E.F.(Vessel Experience Factor) ?



  77. Still waiting for the draft survey program.

  78. Thanks Phlom,

    You could send any materials related to marine survey and surveyor that you have to my email. I will published it on my blog.


  79. I am back. If is any study material that i can send it to you just mail me and i’ll look for it. They are .pdf and .doc.
    I was to my first draft survey. As observer…cause i am still learning :d But it was really interesting. And i used youre specimen as example and it was very good. So thx!

  80. Dear Phlom,

    Thanks, if you have any related articles you could send me one.

    Best Regards,

  81. Dear Chistian,

    Thanks, Yesterday I have discussed by email with my friend Ronald, he told me that he will launch the New Draft Survey Program. For pre-launching, he will be given the raw program in excel to attach on my blog for reviewing by the blog visitors.

    On the last mail, he said that the download link will submit to me on the next 14 days. Then I will post it here. Hope it could be done.


  82. Dear Joseph,

    Welcome, the Draft survey is the same with others science, where everybody can do it as long as he/she has been wilfulness to learn it.

    Draft survey would be more prefer for seaman or the person who has experienced with ship, cargo and port. Firstly, you should need more effort to learn about basic knownledge of the characteristics, specifications, descriptions and terms among them. Then practising the theory you have got is the best way to improve your skill.

    Is there any feedback for Joseph? Just leave your comments!


  83. Hy there! Thanks for this specimen. It is really useful. Hope it is more to come.

  84. Somebody has a basic draft survey programme (in excel for example)?

  85. I am an Accountant. I want to study Draft Survey and Bunkers.
    Any Special Help?

  86. Dear Sadanand, will post it shortly.. Thanks.

  87. Please give specimen report for survey of liquid surveys such as phosporic acid and also explain the derivation for Vessel Experience Factor(V.E.F.)


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