The Water is Lava

Underwater volcanic eruption has caused a huge pumice "raft" that is about 150 kms. Sailors desribed it as being at least 6 inches thich and had pumice chunks that ranged from marble to basketball sized. Sailing through it was "like ploughing a field", there was no water visible.

Interesting sea environment.... What would its (game) effects be? Would it even slow a boat? Maybe polish off some rust and barnacles?
Anything beneath the sea could use the temporary pumice island for shade and cover. Pumice is a useful material - I wonder if it is harvest at sea or just washes up.

We might be worthwhile to set up a 'sticky' thread where we could put weird sea stuff.