One way is to simply have a
deck locker. You can store
paint, gasoline, acetone, hydrochloric acid, and other nasty stuff in it, you can use waterproof plastic containers inside for additional protection. On my
boat I have a number of "wet lockers" that drain over the side (actually, through the underwing). Some contain
propane tanks for the
stove, others contain
paint and other vaporous products, another has lye, oxalic acid, hydrochloric acid and other nasty stuff, each in a waterproof container and secured against rolling and spilling.