7 - How can biofouling be minimized in niche areas?
Niche areas are parts of a craft that are particularly susceptible to biofouling growth due to different water flow conditions, the exposure of the anti-fouling coating system to wear or damage, or areas that may be inadequately coated. For example, any hull projections or indentations that may generate turbulent flow which causes greater wear on the coating. Niche areas may include:
- propellers, thrusters and/or propulsion units;
- rudder stocks and hinges;
- rope guards, stern tube seals and propeller shafts;
- apertures or free flooding spaces;
- areas prone to anti-fouling damage from groundings;
- outlets, inlets, cooling pipes and grates;
- anchors, anchor wells, chains and chain lockers; and
- echo sounders and probes.
Biofouling in the niche areas of your craft can be minimized by ensuring an appropriate anti-fouling coating system is applied, including the entrances to inlet and discharge pipes, rudder fixtures, bow and stern thrusters, propellers and shafts (unless polished), rope cutters, etc. When hauling out and applying an anti-fouling coating system, you need to make sure that you change the positions of blocks or slings to ensure these areas are also coated.
Some niche areas are not protected by an anti-fouling coating system, e.g. anodes. You can minimize biofouling associated with these anodes if they are flush-fitted, or a rubber backing pad is inserted between the anode and the hull, or the gap is caulked. Otherwise, you need to ensure that the hull under the anode and its strap has an anti-fouling coating system suitable for low water flow. If your anodes are attached by recessed bolts, then the recesses should be caulked.
If your craft is equipped with a Marine Growth Prevention System (MGPS) (for example, injections of chemicals in internal seawater systems), it is important that you regularly check correct operation of the MGPS in accordance with the manufacturer's instructions.