Drop Fins

[Bobby P.]

I installed my new RIB on weaver 4" up and 4" out mounting brackets over the weekend. I really like the setup. Easy launch and retrieve. Good piece of mind when underway (rather than towing) or backing into slip. I get a good bit of spray on the lower tube when cruising. Does anyone know if Drop Fins might help reduce the spray? I get most of it when cruising over 12 knots.

Just curious.

Thanks,
Bobby

 

[BB marine]

Bobby, unfortunately the Drop fins are not going to help with the spray. The drop fins will help lift the stern if you feel the added weight has made the boat stern heavy. When I installed the rib on my 8.6 beam C26 the drop fins were a must. The drop fins were really a must without the Rib. That was to help bring the bow down. As I posted earlier the lower tube needs to be offset flush with the hull port side. This causes it to hang past the starboard side hull but the bow of the rib is high enough not to catch water unless you are in rough water going at high cruise. And even then it is minimal.

 

[Bobby P.]

Brian,

I did scootch the dinghy a little to the starboard on the install, but obviously not enough. I had been thinking about adding the drop fins anyway, and because I have a trailer it is easy enough for me to pull and do the install myself. If it might help at all, I was thinking about doing the Drop Fins sooner than later. Do you know which drop fins I should use on the 2017 R31CB?

Thanks much.
Bobby

 

[Red Raven]

Hi Bobby,

Our Dinghy used to catch some spray at high cruise in rough conditions. I added some stainless steel ratcheting straps (spring lines) from the tug stern rail to the dinghy rigid hull (dinghy inside bow eye and lower (port) dinghy transom eye). Tightening these straps really tight actually lifts the dinghy nearly two inches. Lift is created by eliminating play in the weaver clips, the flexibility of the tubes and angle of the weavers grips/eyes. It worked for us.

See this thread for more info.

http://www.tugnuts.com/viewtopic.php?f=2&t=6518&hilit=Spray&start=15

Curt

 

[BB marine]

https://www.defender.com/product.jsp?id=6508000

I assume that the Bennett Tabs on your boat are 12" chord. Measure from transom to end of tab aft. I recommend that you have fins running straight with the keel. Depending on the angle of the transom this may not be straight on the trim tab. The R31 has wide tabs so this will not be difficult to do. My original tabs were 12x12 so I had to make custom drop fins to run them straight with the keel. You will also need (16) 8-32 machine screws 1/2" long with locking nuts SS.

 

[pleeson]

On our C28 we had to take the Weaver brackets to a welding shop and add 4" of height to them. If you stand in the dinghy on the far side the boat will still clip into the brackets ready to hoist and the extra height brings the lower tube out of the spray for all normal cruising conditions.