hydrofoils

[Seabass81]

So here I sit once again thinking what to add to my boat . Last year my boat was really slow to get on plane . It was really really slow with 2 people and 100lbs of water .

My prop is at its optimum pitch but my boat is slightly under power (75hp on a nitro 170) .

I was thinking about a hydrofoil. I have heard some good things about them but I always value the opinions of my fellow hawkers .

So what is your experience with them.

[Lunker Larry]

Big difference in boat size and power, but I had one on a 12ft with a 7.5 Honda once. Anyone who has had a small boat has experienced the problem of keeping the nose down and because of the back end heaviness, difficult boat control at times. I used to put a cinder block in the front of the boat.
I added a Dolphin, I think it was called, onto the cavitation plate. It made an unbelievable difference. Quick to get up on plane, (no longer needed the brick) added speed and increased the boat control by a 100% which was most appreciated in rough water.
I know some of the big bass boats use them to keep from bottoming out when they power out of the shallows.
Anyway, thats my experience with one.
Good luck and hope you get it figured out.

[Andy_L]

Trim tabs over hydrofoil John

[Fishtraks]

Andy...why trim tabs over hydrofoil?? Just curious. I bought a set of NAUTICUS trim tabs (SMART TABS) to cure my porpoising problem, but when I realised I had to drill a dozen holes in my transom to mount them I put them back in the box. It also appears that they might be tricky to adjust for correct attitude etc. So now I have a nice set of trim tabs and actuators on the shelf. Went out and bought a hydrofoil at CTC ($70)....but to mount this on the cavitation plate, looks like I have to remove the bottom end. I would have to drill the holes from the bottom up to mount them as I can't drill STRAIGHT down because of the shape of the lower end. So now I have a hydrofoil and a set of trim tabs on the shelf and I still have to use the big blue jug full of water in the bow when I'm by myself. Any ideas would be appreciated folks. Where do I go to get the hydrofoil mounted??? Some people swear by them, some people say they are dangerous. Any thoughts??

[Wallyboss]

John my Father-in-law had a set on his Princecraft Pro169 it was rated for a 90hp and he had a 50 on it. The Hydrofoil sure helped a lot but he lost a few MPH on top speed with it, got on plane faster though. Which is what your issue is right???

[beachburger]

What about resolving the real issue and upping the size of the motor?

It's more money sure but you don't have to buy a new motor, you'll be able to sell your existing motor to offset a good chunk of the additional cost and you'll probably be happier with your boat. And if you want to upgrade your boat down the road, a bigger motor will be a selling point.

Just a thought.....
Doug

[Seabass81]

Doug I want a bigger motor .

I just bought a new suv and cant afford it now . Next year possibly .

Dan: That is my problem alright . I also expect it to be worse since adding the 24volt motor upfront as well as the extra battery on the back!

[Fishtraks]

Doug...my boat is a 14 ft tinny with a 15HP 4 stroke. I looked into upping the size...best I could do at the time was trading my 07-15hp for an 07-25hp 4 stroke EFI elec start. They wanted $1900 difference. Then I would need another battery, and some heavy duty wiring to hook it all up. ....a little pricey for me...thus the search for a more economical solution. That big blue jug of water in the bow sure is the cheapest fix, but it's a pain.

[beachburger]

Hi Fishtraks. My comment was toward Seabass. I didn't see your post. Sorry.

I went through a 20HP Johnson to 30 HP Yamaha upgrade many years back on my old Princecraft Resorter. I had added a floor and bowmount trolling motor and the 20HP just couldn't push it anymore. As you have found out, it wasn't a cheap upgrade but I was much happier with my boat, so much so that I was OK putting off doing interim boat upgraades until I could afford the boat/motor I really wanted. I didn't upgrade to an electric start with the Yamaha for the reasons you mentioned.

I have a new (very old) 14' tinny and I'm back to using a blue jug in the front. It's ugly but so am I and the fish don't care.....

[beerheart]

I wouldnt think a hydro foil will help much unless you're just not getting the motor up high enough to have the cavitation plate out of the water. The hydros are designed more to keep you on plane at lower speeds and are of coarse, bolted to the cavitation plate. Maybe you want to look at raising your motor up a notch on the transom. If you can (water pressure and flow allow), it will make a world of difference on top end. If you dont already have a ss prop that will help also.

Good luck

[Fishtraks]

Ouch!!, my back hurts just THINKING of pulling over a 30HP motor by hand!!....

[Fishtraks]

What is the theory of using a SS prop....are they typically more "slippery"...ie:less drag than an AL prop??

[Andy_L]

What is the theory of using a SS prop....are they typically more "slippery"...ie:less drag than an AL prop??

they don't flex....aluminium props flex and lose efficiency

[Andy_L]

why tabs over foil? IMHO

the tabs are WAY more adjustable....side to side as well as the porpoising issues. I'd rather drill the transom than the cavitation plate

slows down your troll as well with the tabs stuck down in the water flow. Smart tabs are great...you just have to play a little trial and error to get the resistence right

But as Doug says....best fix IF its doable is to upgrade the motor size.

[beachburger]

Ouch!!, my back hurts just THINKING of pulling over a 30HP motor by hand!!.... Laughing

Then you would be surprised to find out a 1997 Yamaha 30 is no more of a pull than a 2007 Johnson 9.9 (my wife's uncle owns the Yammy now).

For motors in the 9.9 - 30HP range, they should all pull start very easily. Not sure about pull starts on motors bigger than that but you may not need to shell out for an electric start for 30HP or less if you don't want to.