Underwater inspection, hull cleaning and repair, waste disposal, equipment installation and port husbandry.

Waste and residues

• Collection and disposal of sludge, bilge water and oily residues through licensed reception facilities, with the MARPOL Annex I receipts and Oil Record Book entries the vessel needs to hold on file.
• Garbage disposal against the Garbage Record Book, and disposal of expired pyrotechnics and time-expired chemicals.

Underwater services

• Inspection. Underwater inspection in lieu of drydocking where the vessel's class permits it, with video and a written report, and class surveyor attendance arranged where a survey credit is required.
• Hull and propeller cleaning. Fouling removal and propeller polishing at anchorage or alongside. Removing hull fouling restores speed and cuts fuel consumption, so the work usually pays for itself well before the next docking.
• Underwater repair. Wet welding, plate and doubler work, rope guard and sea chest clearance, and damage repair carried out afloat.
• All underwater work is done with the vessel in service, which is the point of it — the alternative is waiting for a docking slot or taking the ship off hire.

Equipment and calibration

• Supply and installation of marine equipment, and calibration or recertification of items that carry a validity date — gas detection instruments, oxygen analysers, pressure gauges, thermometers and test equipment.
• Gas cylinder exchange and refilling, including CO₂, oxygen, acetylene and refrigerants.

Husbandry

Launch and transport arrangements, crew changes and airport transfers, medical appointments, laundry, fresh water supply, and general attendance during the port stay.