[Targan]

I wonder whether kelp beds and sea grass meadows could be a viable source of biomass for the production of alcohol fuels in coastal areas? Or to kick it even more old school, could it be harvested and dried or even scavenged pre-dried from the shoreline and used as-is in wood and coal-fired boilers?

Two-thirds of our planet is covered with water and in shallow coastal seas there are huge amounts of aquatic vegetation. In some parts of the world there are free-floating "islands" of kelp. The reason that the mention of Florida triggered this line of thinking for me is that I know that manatees are found around Florida's coast and manatees are "sea cows". Where you find manatees you will surely find sea grass meadows.