Even though it's always somewhat humorous to see a skimmer in distress, I still feel bad for the officers and crew of USS Guardian (MCM 5), aground in the Sulu Sea. The latest information is here. This picture shows how quickly the water goes from "deep enough" to "oh, crap".
Have you ever been on a boat that was grounded hard enough such that it was unable to move?
Update 0900 25 Jan: It looks like they've decided she'll sink if they pull her off the reef, so they're sending some heavy sealift assets to carry her back to port.