Hello i have got today a waterscoop for under my hull and am wondering how i should fit it,do i drill 1 hole for the nipple to fit through the hull and epoxy it on so it fits like a wedge to the hull or do i cut a rectangle the same size as the scoop then push the scoop in so its totally flush with the hull bottom then epoxy it?At the moment im thinking along the lines of my first way because if it was fitted level with the hull bottom id imagine water may not go in it were as if its fitted like a wedge it would scoop water.I,ve never seen a waterscoop fitted so to be honest im not too sure so all help will be greatly received.Thanks all in advance.Darren

Hi Darren

If you are running a mono hull (deep V) with a surface drive at the transom end....
I would suggest that you do not attempt to rely upon such a pick up for the water cooling.

I say that because once the hull is out of the water running flat out, such a scoop will likely be pulling in fresh air not water.

If you are running such a hull/surface drive set up, I would recommend a water cooling pick up from the transom end of the boat.

The integrated system with modern rudders delivers acceptable results. The pick-up point is always below the water line regardless of how the hull is behaving.

Craig

Hi Craig its for my big boat,i have at the moment got a feed from my rudder but the engine just is not cooling right,when the boats going all i see coming out of the outlet pipe is steam,my rudder im doubting cos it just don,t seem to be supplying enough water,i,ve looked and my rudder only has 1 feed hole at the bottom of the blade,my nitro boat has a similar setup but one hole either side which are staggered abnd that cools lovely n pees well,maybe i need to look at that blade or change it,i,ve tried different pipe going from 3mm up to 4mm but still the same.Im now thinking of one of them feeds that have a short brass pipe cut on an angle to fit near the strut seeing as you don,t think the scoop is suitable for my boat.Thanks Craig certainly saved me cutting my hull only to be exactly the same.Regards Darren

Hi Dazzido.

I have no experience about this at all, but I am a learned boat builder with a feel of what works and what does'nt.
So here is what I will do in the build of my own 56" wooden mono:
Two double waterscoops will be mounted in a couple of solid wedges close to the stern and close to the keel line. This part of the boat will almost never leave the water.
It will not only provide sufficient cooling water, but also some lift, that could make your boat accelerate much faster.
Best thing about the mounting in wedges is that you don't have to make square holes for the waterscoops in the bottom of the hull - only in the wedges.
All done in one "simple" solution.

Cheers!

Woodie

Hey Woodie, Be careful about the 'Wedges' size.
They may very well lift the stern and push the bow down.
I stand to be corrected, but are these not usually flush mounted.

Why are you not using rudder pickups?
They are foolproof and simple to setup.
David

Dazzido. A single pickup should work ok. I believe that most gas boats would use single pickup rudders quite sucessfully. If it's one of the mainstream type, and you want double pickups, simply purchase another rudder blade with double pickups.
Do you have your water cooling lines routed the right way? If it's split between head and exhust flange, are the lines the same length?
David

Hey Kiwi.

Rudder water pickups are no option for me as I will use a double set of MHZ sterndrives.
I haven't really decided this yet, but the wedges should not be too large, just large enough to avoid making a square hole in the hull itself (only 2,4 mm thick birch plywood).
The vacuum behind the wedges could be used for a bailing outlet.
An all-in-one solution!

Cheers!

Woodie.

Thanks David the fault was the standard zenoah water nipples soon as i ran a drill through it was peeing as it should do.Thanks everyone for your help,what an excellent friendly site keep up all the good work.Darren