In the news

Robot fish accepted by real fish -- assumes leadership role in steering the school
Reeling this topic back in...
I visited Bath University, or rather the University of Bath (two different places, one at the top of the hill, one at the bottom) a couple of years back doing a story on biomimcry - they had this bad-ass fish robot which was a bit like your link but also had an undulating fin underneath running the length of the body. Their argument for the mechanics of the technique for propulsion was one of efficiency - it was something insane like 95-98 percent efficient compared to 70 percent efficiency from a traditional rotating prop. It was also ridiculously quiet and they were receiving funding from a nearby company who worked on submarine designs for the navy.

They were also keen to try it out in somewhere like Lake Vostok as, unlike a traditional prop, there were no moving parts (read oily pollutants) which ever made contact with the water, simply a silicone-like skin.

#csb