Customer Reviews

Davis Instruments Doel-Fin Hydrofoil

5 star:		(12)
4 star:		(3)
3 star:		(1)
2 star:		(0)
1 star:		(0)

 

 

I installed the Doel-Fins on my 11.5 foot Avon SuperSport RIB (the S3.45 to be exact). The Avon has an older 2-stroke Evinrude 30 hp motor and the Doel-Fins were easy to install without requiring a right-angle drill. I spent a LOT of time measuring and determining placement before I drilled the holes in my cavitation plate, but once I drilled the holes, the rest of the install took maybe 10 minutes at most.

The good stuff:
The Doel-Fin definitely makes a big difference in two areas - getting up on plane and staying there at lower speeds. In fact, I am now able to stay on plane at speeds as low as about 6-8 mph, which allows me to save fuel and create less of a wake while transiting through harbors. Also, prior to installing the Doel-Fin, the boat had a pretty strong tendency to bang up and down when going into a head sea (swell coming toward the boat). While I wouldn't say it was "porpoising", it was close. After installing the Doel-Fin, the ride into a head sea is much smoother and tends to stay on plane much better when throttling down after cresting a swell.

The not-so-good-stuff:

Really, just two things - 1) Definitely reduced top speed. Prior to the Doel-Fin the boat would do about 31 mph at WOT in a lightly choppy sea. After the Doel-Fin, max speed at WOT seems to be about 27 or 28 mph. This represents about a 10% reduction in top speed. Not a big deal, since I don't really operate the boat at WOT much anyway. 2) The Doel-Fin really, really catches kelp! It is very tricky to get in and around the kelp to fish or dive without snagging the Doel-Fin. When this happens, the usually procedure of reversing the prop briefly doesn't always clear the snag. I usually either have to do a quick reverse followed by a FULL THROTTLE forward push to BBBBRRRRREEEEAAAAKKKK through the kelp, followed by another quick reverse to clear the prop, or I have to shut down the motor and clear the foul by hand. The problem with the latter approach is that if I have pulled anchor, I'll often drift right back into the kelp by the time I have it cleared, which repeats the problem cycle all over again.

Bottom line, its a good addition to a small boat. I found that the fins seemed a bit large for my small motor - I wish they made a smaller size that had less overlap of the cavitation plate.

A fairly good product with some cautions. If you already have stabilizers, this type product has a tendency to make the boat slide around alot in the stern. If I barely use the manufacturer stabilizers it seems to make everything a lot more steady. The Doel-Fin works as advertised in that the boat definitely comes up quicker which is really great! I'm sure it takes a lot of strain off the engine and is helping my GPH on fuel, although I have not had a chance to do an actual measurement yet.
One more thing to think about. The advertisement leads you to assume it will bolt right-on. This was not quite true. Depending on how the fin plates are arranged on your prop, be prepared for some contorsions and acrobatics, not to mention some out of the ordinary tools manipulations to get it installed in the correct place. Once installed, it's great and definitely worth the money.

Had a Doel Fin on my small 15 hp Evinrude that seemed to work well, so decided to give it a shot on my 90hp Yamaha to see if it could fix my cavitation issues. Installation was a snap and had it on in less than 15 minutes. Have been using it for over a month now and my cavitation problems are gone. I have a 15.5' Livingston and used to take forever to get it up on plane. With the Doel Fin, it jumps up on plane as soon as I give it some throttle. I feel that I have way better plane control and my boat also goes faster. I would recommend this product to anybody having cavitation issues. Would buy again if needed.

I just bought a 17ft polar flats boat with a johnson 50 on it. Before I bought this someone had to sit on the front of the boat to plane. I thought about re propping but decided to try this first. worth its weight in gold. now 2 people over 200lbs can sit on the back and it will plane.

We had an 8 HP motor on an inflatable dinghy that we could never get to plane with my husband and I in it. Installed this and the performance was definitely improved -- we could then sometimes plane. However, to really get the performance we wanted, we had to get a larger engine . . . but we put the fin on it, too. Didn't do a before and after comparison, so I can't say how much it helps. However . . . we've recently bought another boat and I'm here buying another fin!

A friend of mine "Grant" FishFraley@gmail.com a great Salmon Steelhead Fishermen had recommended this addition to my motor after showing me the one he had on his 15hp Honda motor. I found mine on Google and ordered it. When it came I followed the simple installation instructions and had it mounted in about 30 minutes. It took me a little longer than the instructions said, but I'm like that.

I had my 8hp Honda Four Stroke mounted on my drift boat and had experienced vision difficulties when I was underway and when I had the motor under full throttle the bow would rise so high out of the water I'd have to turn the boat starboard or port side to see what was in front of me.

After the installation of the of the Doel-Fin I put the boat on the river and what a difference. It brought the bow down to a manageable point where I could see where I was navigating to. I also put a prop protector ring around the prop and it still worked with the Doel-Fin system.

I bought this for my husband. He kept complaining about how long it took his fishing boat to plane in the water. No complaints now. Works for me

This product did everything it claims. Boat planes quicker, stays flatter, handles waves much better. Unsure if top speed dropped. For what it has done for my 20ft I/O I really do not care. Installation was a little rough for me as the holes from top to bottom of the plastic fin did not line up causing me to have to shave the one bolt head down. It is plastic and perhaps not 100% precise. Aside from that small complaint, it was just fine.

I was skeptical, but at this price I figured I would give it a shot. Works as promised, was easy to install, and now my boat planes much easier. All around great value.

I was very happy with the performance of the Dol-Fin I purchased. I put it on a 60 h.p. on a 18ft. deep Vee and it helped me plane quicker and cut down on the bounce when hitting waves. I did lose about 2mph but it is worth the sacrafice