Ocean turbines- a pretty neat idea.

Good luck to them. The idea of tidal current generators has been around for a long time, but the technology doesn't seem to be getting very far very fast. I know a small demonstration project off of Victoria, BC had lots of issues, including with marine fouling (seaweed buildup, etc). There are proposals for several sites near me and investigative licenses have been obtained, but they don't seem to be going anywhere. The UK venture mentioned in the article is probably the most promising of the current initiatives - it has major public and private funding.

Race Rocks demo project end: http://racerocks.ca/energy/tidalremove/tidalremove.htm

Prices seem to be coming in ~$0.20/kWh. Until that can be reduced, seems unlikely to be developed to large scale.