QE2 Portholes - low down/underwater

[Peter Mugridge]

Grimm Wheel = a kind of experimental high-efficiency propellor system, but it didn't really work.  There's a topic on here somewhere about them.  I'll have a look later and link it, unless someone else beats me to it.

[Rod]

http://marinewiki.org/index.php/Vane_Wheels

And what does Wiki give us??
 A Rob Lightbody picture. Way to go Rob!!