"The purpose of having left hand and right hand props installed on a twin screw vessel is in order to stop one propellor sucking water away from the other, therefore making one of the props inefficient by starving it of water that it needs to develop thrust. "
Well, they say you learn something new every day.
But I'm not sure that the above is a learning experience!
I've never seen that postulated in any analysis of single versus twin screw performance for high speed naval craft. Including those done by the USN Design Bureau. Which prop would under which circumstances 'suck' water away from the other?
The main reason for using opposite prop rotation on a twin screw setup is to cancel out the torque reaction of each screw on the hull (regardless of inboard or outboard rotation for ahead). This effect is even more noticeable on models as they don't have the mass inertia of their big bruvvers😉
I do agree with you though that inboard rotation should be used especially if you have twin screws with a single rudder. Like most WW2 destroyers for instance.
USN calculations and practical trials showed that for twin screw small ships; such as Fast Attack Craft, FPBs, Corvettes etc, with twin rudders that outboard turning screws gave a minimal advantage in manoeuvrability when the rudders were set slightly inboard of the shafts.
Since USS Crocket was a Gunboat (which would now be called an FAC) capable of 50 knots and seems to have two rudders it would seem logical to make the screws outward turning on drspock's model.
Cheers, Doug 😎