Thanks to Nick for sending this over. Gizmag have an article about a personal two-man submarine that is apparently capable of descending to 1,000 feet. It is powered by a bank of batteries that can apparently provide up to 6 hours of continuous underwater sight-seeing. Although at that depth, you’ll need the 4 external 150 watt quartz halogen lights.
You can find out more, should you really want to, from gizmag’s website.