I am reminded of a reply I got on one other post when someone said they found 'wreckage' on the shore and in the water on the reef. In short it isn't there. Now that is not to say I am sold on that idea, but I have never been to the island, I don't know the environment. So I don't know if something could be on the reef for an extended period of time (Such as a B17 or Electra) and wash away. I have to take their judgement on it. However I will say this, I see something in this photo, and the others. It does look like a plane, but I don't know if it is one or what it is. Something is there... of this I am sure.
Also regarding the floating of the planes when in the water. I can see how the B17 could float its way to Gardner over time. If it was in once peace, which I understand it was. However if this is the place where AE landed the Electra, and it was on the reef then I don't think it went far. Think about it, if that ship was there taking the pounding from the surf, it can't be in one peace. I bet it is in a million peaces all up and down the cliff side of the reef.
Just my thoughts.