I have a wood dock over a lake. It is time to clean and seal the dock. I am planning on pressure washing the dock first, then I am planning to have a clear seal. Looking at products in Lowe's and Depot I can't determine what is safe to use. I don't want it to look like a BP spill or kill any life forms.
They do make stain specifically for marine use. Doesn't say specifically that it's environmentally friendly, but the MSDS sheet does say it's water soluble. The same manufacturer has environmentally friendly stains as well, but I have no idea how well they might work (or exactly what "environmentally friendly" means to them).