Bugger.
Given proximity of the yatchs it looks like they went down with the ship.
Abc tv aired the emergency call from one of the yatchs, the plane was on the surface for a short time because during the call it was reported in present tense as "sinking" rather than have sunk. Police have suggested this was around 30 seconds.
Assuming they were not wearing helmets, I cant help but wonder if being knocked unconcious may have had a role in their inability to exit the craft.
Mickjoebill