Ngaire Here interrupting Kens pictures to answer Helen's question

Forgive me, I can be a bit dense at times: for Sumo, no wet landings until we leave Japanese islands? CORRECT

But no boots then because it will be hot? No waterproof pants either then? CORRECT unless you want to wear them to keep dry but light rain gear would work as well. You need shoes you can step out of the zodiac into the sea that are waterproof instead of the waterproof boots.

If for any reason you need boots (mud or some such thing) they have those onboard.