Hi Ho Silver! Wish I'd thought of the teeth in the mouth of the estuary, that is a perfect line for this situation.
In passing, a real lobster measuring about 4 feet in length was once encountered by a diver in Fowey harbour. It attacked him as he was doing maintenance work at the China Clay Dock.
The Lobster obviously came off worst, as details of it's length and weight used to be reported on the wall of the local fish shop. No details of what it tasted like, however!

FC