A great addition to cleaning boats in a marina will be also to take care of any buildings that are on or near the water, and the docks themselves as they can get covered with bird droppings, dirt, spider webs, and anything like that. Wood decks, docks and piers are subject to attack by moss, insects, sun, salt spray, fish guts, water damage, physical wear, foot traffic, rain, snow, morning dew. All of which are quickly absorbed into unprotected wood causing it to swell, deteriorate and chip away, also causing shrinking, warping, splitting, cracking and discoloration.

Because docks are horizontal, they hold water and snow for prolonged lengths of time. The dampness attracts pollen and fungal spores, which collect and cause this ugly discoloration and black algae. And, of course, these horizontal surfaces are subject to 40 to 50% more direct sunlight than their vertical counterparts. The bottom of a dock may be as much as 50 to 60