3 Conditions for in-water survey
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - Circulars - Maritime Safety Committee - MSC.1/Circular.1348 – Guidelines for the Assessment of Technical Provisions for the Performance of an In-Water Survey in Lieu of Bottom Inspection in Dry-Dock – (2 June 2010) - Annex – Guidelines for the Assessment of Technical Provisions for the Performance of an In-Water Survey in Lieu of Bottom Inspection in Dry-Dock to Permit one Dry-Dock Examination in any Five-Year Period for Passenger Ships Other than Ro-Ro Passenger Ships - 3 Conditions for in-water survey

3 Conditions for in-water survey

  3.1 The Administration or its RO should be satisfied that conditions for survey are sufficient to complete the survey satisfactorily. Points to consider may include those below, and classification society requirements should also support this aim.

  3.2.1 The IWS should be carried out by a diving company that is approved by the Administration or its RO, and in accordance with an approved plan.

  3.2.2 Diving companies providing services on behalf of the owner of a ship or a mobile offshore unit (such as measurements, tests, surveys or maintenance of safety systems and equipment), the results of which are used by the surveyors in making decisions affecting certification, should be subject to approval by the Administration or its RO.

  3.2.3 Diving companies should undergo an approval process, including training, and should be certified at intervals not exceeding five years, and may be subject to intermediate audit.

  3.2.4. The in-water survey should be performed to the satisfaction of the attending Administration or RO surveyor who is properly trained and authorized to conduct such surveys. Training and qualification of the attending authorized surveyor from an RO should be in accordance with the quality system requirements of the RO and resolution A.739(18), as verified by periodic audit.

  3.3 The in-water survey should be carried out at an agreed geographical location with the ship at a suitable draught in an area that has been demonstrated to have sheltered waters and with weak tidal streams and currents. The weather at the time of the survey should be conducive to a safe and effective IWS.

  3.4 Surveys of the underwater body should be carried out in sufficiently clear and calm waters. In general, for example, a significant portion of the propeller or rudder should be clearly observed from a single view. Visibility and water conditions should be suitable to provide sufficient evidence to be able to draw a conclusion that the hull inspection requirements have been met and the hull is in satisfactory condition.

  3.5 The surveyor should be satisfied that the hull marking and mapping as well as the method of pictorial presentation are satisfactory. To facilitate an efficient survey it is recommended that the underwater hull and fittings are permanently and clearly marked externally (including tank boundaries).

  3.6 Sufficient information to the satisfaction of the attending surveyor, including specific plans to facilitate the survey, should be available on board in order to ensure a full assessment and survey.

  3.7 Unless accessible from outside with the aid of the ship's trim and/or heel, underwater parts should be surveyed and/or relevant maintenance work should be carried out with assistance by a diver to the satisfaction of the attending surveyor. The survey should include CCTV monitoring of the IWS, together with electronic video and still picture (if required and where appropriate) recording of the ship's hull, appendages, sea-chests and other elements of the survey. There should be good two-way communication between the diver and the personnel at the surface, including the surveyor.

  3.8 The hull below the waterline should be sufficiently clean to the satisfaction of the surveyor and diver so as to be able to ascertain the physical condition of the hull and coating.

  3.9 Interior sections of the hull plating should be made available for inspection to the same extent as if the ship were in dry-dock.


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