A NASA team of six is wrapping up an 18 underwater mission after testing, among other things, how astronauts might interact with robotic space explorers.  The team, designated NEEMO 9, has lived in the Aquarius undersea habitat near Key Largo, in the Florida Keys.

Activities have included simulated moonwalks and remote, robotic surgery with an artificial two second Earth-to-Moon communications delay.  The surgery was performed by a doctor 1300 miles distant in the city of Hamilton, Ontario Canada.

MSNBC Story...

Older NEEMO 7 story on Space.com...

This is the BOB diving vehicle (Breathing Observation Bubble) which is built as a way for chaperoned non-divers to experience the underwater world.  My impression is that it's a powered, full-body SCUBA helmet.  I mean that in a good way though - I'd like to try it. 

The link above has some technical stats: 2.5kt top speed from the 12V electrical drive, 58lbs weight, and a 40ft max depth. 

These have been around for awhile, built I think by the Bellaqua Personal Submersibles company which seems to be defunct.  I don't know how many BOBs were built but the first website listed here runs trips from Sand Key, Florida which is near Key Largo and down in the Florida Keys.

  http://www.sfdj.com/bob/bob.htm

A replica whaling ship, the Carthaginian, was recently sunk off the Maui coast.  It landed upright on the sandy bottom in 95 feet of water about a half mile offshore of this popular Hawaiian island.  The hope is that this wreck will attract marine life and provide an interesting destination for scuba divers and underwater tourists aboard Atlantis' tourist submarine that operates along the Maui coast.

  Press release...

Have you listened to a podcast yet?  I'm starting to get into it and am using Apple's iTunes software which makes it easy to find and subscribe to podcasts.

Here's one of interest to undersea explorers and particularly technical scuba divers.  There are a number of shows  recorded already on, for example, underwater photography, mixed gas diving and rebreathers.

Pod Diver website

A rebreather is a type of breathing equipment that provides a breathing gas containing oxygen and recycles exhaled gas. This recycling reduces the volume of breathing gas used, making a rebreather a lightweight and compact breathing set for long durations in environments where humans cannot safely breathe from the atmosphere.

Rebreather technology is used in many environments:

• underwater - where it is sometimes known as "closed circuit scuba" as opposed to Aqua-Lung-type equipment, which is known as "open circuit scuba".
• mine rescue and in industry - where poisonous gases may be present or oxygen may be absent.
• space suits - the outer space is a vacuum where there is no oxygen to support life.
• Hospital anaesthesia breathing systems - to supply controlled proportions of gases to patients without altering the atmosphere the staff breathe.
• submarines and hyperbaric oxygen therapy chambers - where the gas in the habitat must remain safe. Here the rebreather is big and is connected to the air in the habitat.

As a person breathes, the body consumes oxygen and makes carbon dioxide. A person with an open-circuit breathing set typically only uses about a quarter of the oxygen in the air that is breathed in. The rest is breathed out along with the nitrogen...