Before a draft survey, the vessel should have her hydrostatic and tank calibration tables to hand, ballast tanks pressed up or empty wherever possible, ballast and bunker transfers stopped for the survey and safe access to all draught marks arranged. Cargo interests should confirm the contractual measurement clause, the declared quantity and the party in whose name the report will be issued.
Which documents should be ready on board?
For the survey to start without delay, the documents used in the calculation should be available when the surveyor boards. Missing or outdated tables directly undermine the reliability of the result.
- Approved hydrostatic tables and any trim correction tables
- Calibration (sounding or ullage) tables for ballast, fresh water, bunker and other tanks
- Draught mark plan showing distances from the perpendiculars
- Light ship weight and LBP
- Draft survey records and constants from previous voyages
- Current bunker, lube oil and fresh water figures from the chief engineer
How should ballast and other tanks be prepared?
Slack tanks make soundings uncertain because of trim and list, so ballast tanks should ideally be pressed up or completely empty. For tanks declared empty, any unpumpable water should be sounded or recorded.
During the survey, operations that change weights on board, such as ballasting, bunker transfers and fresh water production, should be stopped. If bunkering is planned while the survey is under way, the surveyor should be told in advance.
What is needed for the draught marks and access?
All six draught marks should be legible. Marks that are hard to read because of rust or fouling should be checked beforehand, and a boat, accommodation ladder or pilot ladder arranged for offshore side readings.
For surveys at night, the mark areas need adequate lighting. Correcting any list as far as possible and keeping the vessel tight alongside on her moorings both help produce more accurate readings.
What should the crew focus on during the survey?
Having an officer accompany the surveyor allows readings and tank figures to be cross-checked immediately. Sounding pipes should be open and clear, with sounding tapes and water-finding paste ready.
Deck cranes, hatch covers and other movable weights should preferably be in a similar position at the initial and final surveys. Reviewing the calculation sheet together at the end helps resolve inconsistencies before the vessel sails.
What should cargo interests and agents tell the surveyor in advance?
Sharing key information before the operation lets the surveyor work to the right scope. It determines the timing of the readings and what the report will contain.
- Vessel name, IMO number, berth and estimated time of berthing
- Cargo type, declared quantity and any shore scale figures
- Survey method and special instructions in the contract
- Need for interim surveys and any plan to split the parcel
- Party the report is issued to and the distribution list
Which records should be checked once the survey is finished?
When the survey is complete, the calculation sheet, draught readings and tank figures should be reviewed one last time with the officer on duty. Start and finish times, weather and sea conditions and anything unusual that may have affected the readings should be recorded.
Leaving a signed copy of the calculation sheet on board and confirming the distribution list for the agent and cargo interests prevents missing paperwork later. Where interim surveys were carried out, their records should be kept together with the final report so the whole operation can be reconstructed if questions arise.
What safety points apply on survey day?
Draught readings are taken from the quay edge, from ladders or from a boat, all of which carry a risk of falls and of going overboard. Suitable PPE, a lifejacket and safe access arrangements are preconditions; if weather and sea do not allow safe readings, the survey should be postponed.
Tank soundings should not require entry into enclosed spaces and should be taken through sounding pipes from deck. Karan Gözetim provides draft survey services from its base in Gemlik; preparation requirements and scope are shared with the parties at quotation stage.
Frequently asked questions
What if tanks cannot be pressed up or emptied?
The survey can still go ahead, but trim and list corrections are applied to the soundings of slack tanks and their potential influence on the result is noted in the report. Keeping the number of slack tanks to a minimum is advisable.
How much notice should the surveyor be given?
Notice should be given as soon as the vessel's estimated time of berthing is firm, so that documents and the survey plan can be prepared. Any changes in timing should be passed on promptly so that readings are not missed.
Why are constants from previous voyages requested?
Comparing the newly found constant with historical values helps reveal any error overlooked during the survey. A marked deviation is a signal to repeat tank or draught checks.
Topics
- draft survey checklist
- draft survey preparation
- documents required for draft survey
- chief officer draft survey
- ballast tank preparation
- pre-survey checklist bulk carrier