I remember getting on a boat, but assuredly not that one.

I'm presuming everybody on that vessel was abducted, most likely drugged. Everyone living, anyway. I...can't explain what happened to the pirates.

[No, he really can't. He tried to look them over, but between the seasickness and the decay, there wasn't anything specific he could determine. If he'd had someone with him with a background in autopsies or even medicine, perhaps he could have gotten further, but Sherlock's own knowledge -- and stomach -- proved to be insufficient.]