I doubt many Old salts would have encountered something like that.
I would have thought with todays technology, that satillites should surely be able to see something like this well in advance of it piercing the surface.
For God so loved the world..........He didn't send a committee.
Nothing like a sea of pumice, but did spend a day drifting towards an active volcano, while we sorted out some major condenseritis. Blew a bunch of condenser tubes when we steamed through a herd of jellyfish. IIRC, it was in your neighbourhood Wheels.