Mount these by machining a small rectangular hole near the transom on the underside of the hull allowing the aluminium rebate to seat nicely. Then Flow coat a small amount of Epoxy or similar adhesive mixed with a thixotropic compound for the perfect rigid installation. 

If you do it well there will be minimal filling and fairing underneath and you'll have a seriously sleek look. Stuff the holes and spray them over nicely once complete and you wont even know they are there until youre hammering it along and your outlets are shooting water like there is no tomorrow.

We have fitted these to our medium size Cat and they produce a good high flow rate through the electrical cooling system. (picture of the finish above. Forgive the look, this hull has had a hard life and its time to move to a donor :( 

Need some advice or just want to have a chat? Get in touch. We are more than happy to help guide you through it all. :)