Looks like you enabled party mode. lol
You should be able to edit the "right click" button in the controls menu of the launcher. Then just hold down that button when the hammer is equipped to open the selection wheel.
A row of every item, but not just one of each, got stuck just past half my stamina's range from the raft. I swam out to it and was able to pick it up, but was too far to get back. Not to mention the shark soon caught up.