U/W Ship’s Maintenance

From the last up to the next Drydocking, a vessel needs some UnderWater maintenance works, to solves the relevant problems.

Theoretically if a vessel is coated by good antifouling at drydock, is for five years.

Essential precondition is the vessel to be sailing continuously.

If a vessel drop anchor or stay in a harbour for long time, then begins adhesion of some marine micro-organisms at all u/w parts.

Marine micro-organisms growth, depends the remaining time and the location with parameters like water temperature, water visibility, sea/fresh water, current, swell.

Marine growth has as result to increasing the “slipping”, as consequence is to decreasing the speed and increasing the fuel consumption.

Solution is to carry out a “hull cleaning“.

Anodes applied for the period of 5 years. During  intermediate survey ( or later ) anodes wastage appears approx. 90-100%.

Solution is to carry out “anodes replacement” bolted or by welding.

Some overboard valves stuck or leaking but to carry out the valve repair ( cleaning or replacement ) is necessary to carry out “plugging of overboard“.

Same for sea chest,