So this guy is for vambraces of ro, seemingly a bigger pain in the ass than any other piece. I looked for him for over 2 hours a monthish ago, following the comments on alla trying to find it. I couldn't report a bug with solro without solro being out so have been waiting for it to come out.
I brought a 50 druid with me (tonight) to help me track. He ran around the island and couldn't find it, and I visited my favorite spawn points and couldn't find it. He's supposedly a 2 hour spawn? so maaaaybe he wasn't up? but I doubt anyone killed it..
One of the comments says that the plague shark is linked to the boat, so that's why I think it may be bugged.
http://eqbeastiary.allakhazam.com/search.shtml?id=3703
link to the plague shark