By using something every skipper has on board
Scrubbing off on piles is a low cost way to clean your boat’s bottom and carry out maintenance below the waterline – but scrapings and runoff can enter the river and pollute it. One thing that can help is to stretch a line across down-hill from your boat. This will catch any solids while letting water runoff – and you can pick up the bits later.
Visit Fox’s for all your chandlery needs – http://www.foxsonline.com/