The River Hamble Harbour Authority

Maintenance piles

There are three sets of public Maintenance piles within the Harbour. These are commonly used as a relatively cheap method of inspecting and working on boat hulls which would normally be below the water line. The range of activities which takes place at these sites ranges from simple hull inspection to the changing of props, removing ropes or nets from fouled propellers to changing anodes.

The maintenance piles have also been used to remove and apply antifouling paint.  This guidance note is aimed to provide advice in relation to antifouling as the activity presents a risk of pollution which must me managed safely to reduce the risk.

Anti-foul works by providing a protective layer on the hull of vessels which is toxic and prevents a build up of marine organisms below the water line. (It acts by slowly leaching biocide into the area immediately adjacent to the hull, and requires a certain amount of movement through the water to be most effective).

There are many well known reports which highlight the toxic effects on non-target species by older tributyltin (TBT) paints, which are now banned on craft below 25m in length, but still in use on larger craft (e.g. tankers, cargo vessels). Similar evidence suggests that this is also true of modern paints, although the effects on non-target species is not so well understood.

The legislation which governs the control of pollution within a river such as the Hamble is the Water Resources Act 1991, the most pertinent section is shown.

Whilst this legislation may seem quite onerous a few simple precautions can easily ensure that someone does not fall foul of it.

  • If scraping a hull try to do so over a tarpaulin or similar, to collect the scrapings. Try to arrange for the vessel to be lifted ashore for this kind of activity.
  • When scrubbing or using a pressure washer use the minimum amount of pressure required to remove the growth. By scrubbing too hard you will also be removing the protection of the anti-foul by removing the paint itself. If run off is heavily coloured you are using too much force.
  • Do not use detergent in washing water.
  • Try not to work on a rising tide as this will trap residues in the vicinity of the work.
  • When applying new layers of paint be careful not to spill any into the River. Do not leave paint cans open unless you are working from them, to avoid accidental spillage.
  • Always apply new paint according to the manufacturer's instructions.
  • Dispose of any scrapings, paint tins, brushes and other materials in an appropriate way. Do not put them into rubbish bins unless they are specifically designated for that purpose.

What alternatives are there?

There are several choices, but their suitability varies according to boat type and the amount of use they get.

  • If the vessel is small and can be easily stored ashore, dry sailing might be the alternative for you.
  • Silicon based antifoul is only really suited to fast craft, which get a lot of use, and can be expensive.
  • Ceramic coatings are a good alternative on fibreglass and metal hulls.


Water Resources Act 1991 Chapter II Section 85

(1) A person contravenes this section if he causes or knowingly permits any poisonous, noxious or pollution matter or any solid waste matter to enter any controlled waters.

(2) A person contravenes this section if he causes or knowingly permits any matter, other than trade effluent or sewage effluent, to enter controlled waters by being discharged from a drain or sewer in contravention of a prohibition.

Further information on how boat users can protect the marine environment at The Green Blue