I think it's called a venturi pick up, like a scoop facing forward to collect water as you're underway. I think y-knot has installed on on his surtees, drop him a PM.

Thanks Guys, I figured as much was looking to save time by using someone elses experience on the same boat. 

Torpedo, did you position it to either side if the ballast opening or under the opening.

Sweet torpedo, I'm going to try a flexible scoop as we often launch and retrieve in shallow water. But I know exactly where you mean, thanks.

Here is an old thread on tuna tubes on Surtees 5.5 

I have a little Frewza that has tuna tubes installed with the pump in the outboard pod. I will take some pics of the pickup/setup for you and post them tomorrow night. its works perfectly at rest and while underway.

ok mate for what its worth the rule has to be blow the water line to work not it has to be in the lowest part of the boat a skin fitting is the go with a scope, you would think they work just from the hydraulics etc but having a scope forces water into the pick up, now they are not 100% come off a wave get air-borne or roll and you will air lock the system, now I am on a 38ft boat and it happens and if your in a trailer boat then no doubt you will jump and bump your way along.

wont work on a surtee's becuase of the ballast keel, but have setup like that on my new boat with a forward facing scoop and works much better and pump doesn't sit in the water