Nice one, Bart!

A couple of ideas - with regards to industry, could algae-derived biofuel be feasible, as kelp is basically big algae. Even if it was for local (global) consumption?
Floating cities / large luxury liners - if this is a holiday world, would there be scope for there to be large resort-barges, or floating cities? Would these need to be covered on the map?

Just some food for thought