Outboard hydrofoils?

[donbarile]

I'm putting together the last bits and pieces for a 14' Zodiac I picked up.
It's got a 25 horse 2-stroke Merc, which I just had inspected and tuned.
The mechanic suggested a hydrofoil might be a good idea, to cut down
on porpoising. I expect I'll only be going out with two divers and probably
four or six tanks. Anyone have any experience with/without a hydofoil,
and if so, after reading all the hype and testimonials, is there a better
one or are they functionally equivalent?

Don

 

[DA Aquamaster]

I have used hydrofoils on larger outboards equipped with power trim and tilt. They usually help the boat get up on plane sooner/better and generally improve the trim authority which can be an advantage if the boat is not optimally loaded.

At the same time however, the extra trim authority can get you in trouble if you abuse things too badly load wise. In some situations, the bow can dig in after quick cuts in power if too much trim is used to offset a boat loaded too heavily forward.

I am not sure how well a hydrofoil would work on a smaller non trimming motor like a tiller operated 25 horse motor on an inflatable.

My thought is try it first without the hydrofoil and see if you have any problems. If you don't need it, don't add it. They are relatively easy to install but normally require holes to be drilled in the anti-cavitation plate on the lower unit, so taking them back off is an option, but leaves some unsightly holes that don't do good things for the resale value of your motor.

 

[ShakaZulu]

Don't think you'll have this problem with a 25HP, but if you are jumping any waves, the hydros will break off the anti-cavition plates on either side of the shaft. Yes, they do help though.

 

[Chuck Tribolet]

Your profiles says Monterey. The hydrofoils collect kelp.

My attitude on them is that if they really were better, the
outboard manufacturers, who are in an EXTREMELY
competitive biz, would build them in.

 

[donbarile]

True. I got to thinking about the kelp as well. I guess I'll opt out of the idea altogether.
So, that option being out of the way... I have a Garmin GPS V, which, while small screened, non-color etc, is still compatible with the Blue Water cd's. I added waypoints for the buoys and a few other points of interest around the peninsula, and I plan on wiring it to my Raymarine DS400 so GPS coordinates come through on the larger color screen. Question is... and really should be a new topic ... are the Blue Water cds worthwhile, moreso than just using the surrounding areas of water on the [Garmin] Salinas map. Haven't tried navigating with it "offroad" yet, and I'm not sure it's going to work as well as I surmise.

Don

Your profiles says Monterey. The hydrofoils collect kelp.

My attitude on them is that if they really were better, the
outboard manufacturers, who are in an EXTREMELY
competitive biz, would build them in.

 

[Chuck Tribolet]

I find the BlueCharts very useful for familiarizing myself
with an area. I do run with them turned off most of the
time because at least on my Garmin GPSMAP 162, they
slow down the screen updating.

In practice, you won't use the numbers. Create waypoints
and routes, and you use those.

See http://www.garlic.com/~triblet/swell/gps.html
for some Monterey waypoints.

 

[Tom Winters]

I had one of those hydrofoils on my commercial dive boat in Hawaii. It made a nice step climbing in. You would have to really go airborne to snap it off on a wave - I regularly went between Oahu and Molokai getting slammed the whole time over. On your 14-foot Zodiac, it might help with the trim. Good luck powering through kelp though, with or without the wing on.

 

[marcurts]

I have used these hydrofoils on all my outboards from a 40 hp to a 120 hp and they made a big difference. Better gas consumption and allot more stability. I highly recommend them. See Cabela's catalog, that's where I got mine from.

 

[donbarile]

Interesting. I'll probably still err on the side of minimalism, until the first time
I get airborne, anyway. I was really hoping on staying out of kelp, but I guess there's no sure way to guarantee that.

I did pick up the BlueChart cd and it looks like it will be pretty useful. Managed to find
a wreck above Point Pinos, but it seems to be in 300 fsw, just.... out of reach. Anyway, I hijacked all of your waypoints, Chuck, so thanks.

Don

 

[Chuck Tribolet]

There is no way to stay out of the kelp. You can pick up drift kelp just cruising across
the bay. You boat can drift into the kelp bed while you are diving and the wind changes.
Or you can just plain screw up. Or you can go in deliberately under exceptional
circumstances (rescue). I've done all four.

Kelp is bad stuff around motors, mostly because it covers the cooling intakes and
causes overheating. An audible overheat alarm should be considered mandatory in kelp country. My overheat alarm has gone off three times because of kelp. Two of them
were just motoring across the bay and a piece of drift kelp wrapped just wrong.


Chuck