Corrections check list

OBSERVED DRAUGHTS: Forward...P & S                aft...P & S               midships...P & S

Mean values, ie. draughts at centreline, forward, aft and midships.

Correct from marks to perpendicular and midships positions. Misplacement opposite to trim, then positive (+) Misplacement same as trim, then negative (-)

Hog/sag correction (mean of mean of means, or similar). negative (-) for hog          positive (+) for sag

CORRECTED MEAN DRAUGHT ... to enter hydrostatic tables.

Displacement from displacement table.

First trim correction or Correction for layer (in tonnes). LCF same as trim, then positive (+) LCF opposite to trim, then negative (-)

Second trim correction (in tonnes). Always positive (+)

List correction (in tonnes). Always positive (+)

Correction for density. Less than salt water density, then negative (-)

CORRECTED DISPLACEMENT.

Information check list

GENERAL INFORMATION

Ship's name                                                      Call letters                                                  Port of registry

Flag                                                                  Year built                                                   Master

Owners                                                            Owner's address                                         Owner's agent

Manager/operator                                             Charterer                                                    Charterer's agent

Shipper                                                            Chief Officer                                              Chief Engineer

Surveyor/s                                                       P&l correspondent                                     Ship's location

Survey requested by:                                       Survey on account of:                                Type of cargo

Weather conditions                                          Date and time of arrival

THE STABILITY INFORMATION BOOK

Length between perpendiculars

Extreme and moulded breadth

Overall and moulded depth

Summer draught and freeboard

Summer displacement and deadweight

Misplacement of draught marks from perpendiculars and midships

Lightship displacement with lightship constant

Hydrostatic particulars:

Displacement, TPC, MCTC, LCB, LCF

Capacity plans and tables

Correction tables:

Trim

Position of marks

List

Hull deflection

PLANS

General arrangement plan

Profile plan indicating each space in the ship

OTHER SOURCES

Sounding tables and corrections for trim

Quantity of bunkers

Check list of reservations

(Not an exhaustive list)

Height of waves / swell	Clarity of draught marks
State of tide - underkeel clearance	Squat effects
Variations in density	Daytime / night-time
Anchors moved, in or out	Ice / snow on deck
Quantity of bilges pumped	Residue in tanks
Suspect calibrations	Ship movements

Documentation and information

Surveyors and ship's officers should discuss documentation details and the location and state of all compartments. The instruction pages of the stability information book and calibration tables should be studied and a check made of the tank capacities with the capacity plan. It should be remembered that the port and starboard tanks may not be the same and consequently have separate calibration tables.

The base for measurement of vertical heights, the reference point for longitudinal measurements, the units and the sign conventions used in the tables must all be verified. The units used in the correction tables should also be carefully noted because there is sometimes a mixture of units and sign conventions contained within the same documentation. The whole survey should be conducted using the units of the ship and the final result changed to a suitable unit, if necessary. When feet and inches are the standard unit, convert to feet and decimals of a foot for the convenience of a calculator.

The full sounding depths of tanks, the summer draught and freeboard and the record of recent tank soundings should be noted.

Equipment check list

Sample jar and water sample bucket with line

Ballast tank dipper with line

Small hand pump with hose for taking samples

Draught survey hydrometer with certificate

Steel sounding tape with graduations in metres and feet

Water finding paste

Draught/freeboard measuring device

Manometer if some draughts are impossible to read, plus a long measuring tape

Plastic tube with plug, to act as sounding pipe extension

Boat available to read inaccessible draughts

Pilot ladder on board ready for obtaining draughts

Documentation

Pocket computer with draught survey program or calculator