Here's a jetski like watercraft which is complete covered and shaped like a dolphin. It can only submerge up to two feet but it can do rolls and dives within that two feet. Additionally they claim it can jump up to 10 feet out of the water and is powered by a car size 300 hp engine. The cockpit glass of the watercraft is from an F-18 and is about half an inch think which lets it withstand it hitting the water. In the photo on the main site for the watercraft it looks to have two seats in it but in the video it seems like it only has one seat.
Here is an article about a mutant dolphin which was caught recently that had four flippers instead of the 'normal' two. I've circled the two extra flippers in the photo to the right. The flippers look normal but other dolphins don't have them and only�a few times previously have four fins been recorded on dolphins.�The article claims�dolphins use to be land animals millions of years ago and these fins are a left over trait from that. Additionally grow leg buds before they are born but they disappear before birth. So there you have it. Mutant dolphins for the win.
Over on Yahoo one of the most emailed photos right now is this picture of a bionic dolphin. Apparently the submergable is built to look like a dolphin and can travel at 40 mph on the surface and 20 mph underwater. It can hold two people as well but it doesn't say how long it can stay under water or what the battery life on it is. If you ask me it looks like they need to add a windshield wiper because the window is all fogged up and they probably can't even see out of there. It also looks like that to hold two people they would have to be laying down on top of each other.