I can't find the two hollow honeycombs in the second (beach) world. I went to a website that said one is on a crate in the water, and that the other one is on a wall outside the island. I have been on every crate and have not seen a hollow honeycomb, and I have no idea what they mean be a wall outside the island.

Could anyone tell me where these two honeycombs are located?

Well there's one on a crate.And what they mean by wall
is that it is in a corner of the island in the water
near the tower that you climb up to find a tresure chest.
It's not on the tower it's by a "wall".
I know it's confusing but it's all I could think of
to say.

I remember one of the honeycombs being underwater, in some corner I think. You have to swim and avoid the shark to get it...

Try reading through a walkthrough (just search google).

There are walkthroughs on Neoseeker. He doesn't need to go elsewhere.