Do the Class Societies or IACS accept to credit an in-water bottom survey during night time?
Theoretically speaking there must be enough visibility in order to check thoroughly vessel’s hull.
As per MSC.1/Circ.1348 under 3.2.4 the in-water survey shall be performed to the satisfaction of the attending Administration or RO surveyor, while under 3.4. surveys of the underwater body should be carried out in sufficiently clear and calm waters.
In that respect, provided that the visibility of the water is sufficient (this can also be confirmed by the diving company), the class society should not decline to credit the relevant survey.
According to classification rules, following conditions are necessary for a successful bottom survey afloat:
— the water conditions at the location of the survey shall be satisfactory with respect to visibility, current, swell, etc.
— the cleanliness of the hull below the waterline
— an approved company shall be used in the survey, using pictorial equipment
— a report shall be presented
— location of possible damage shall be ascertained
— the survey shall be witnessed by a surveyor of the Society.
A night in-water bottom survey is not prohibited but for practical reasons, it is not not recommended. Damages on hull plating and appendages are not easily seen in the dark.