For more details and a decent PDF try

http://www.akermarine.com/pdf/PV85-br-web.pdf

Far a much more detailed overview, including a complete layout of the OPVs, try

http://www.sname.org/sections/pacific_northwest/images/SNAME%20PNW%20-%20NZ%20OPV%20Presentation.pdf

I found the latter very helpful in building my 1:72 r/c derivative of the OPV

Unicorn