Back to the main site

Strakes at slower speeds

Dan S

Dan S

Well-Known Member
Messages
133
Reaction score
28
Location
Minnesota but boat in NW Wisc.
My boat came in.  It's a 21SLX with a 115HP Yamaha, undersheeting, and open lifting strakes.  What is the performance like at slower speeds with strakes, say 15-22MPH?  Bennington's option list says for use with motors of at least 115HP and speeds above 30MPH.  Obviously i won't be traveling at 30+ MPH most of the time so I'm wondering what to expect at slower speeds.  Thanks, Dan
 
Whoops!  Of course I meant STRAKES and not starkes.  Sorry to those who thought Bennington was offering a new option.
 
You will feel a difference under 10 mph. The bow will start to lift. You'll feel it.
 
lakeliving said:
You will feel a difference under 10 mph. The bow will start to lift. You'll feel it.
Click to expand...


Hmmmm ... wonder if that would help mine?   :blink:
 
When I am cruising at pace faster-than-puttering, but slower-than-get-there-fast...I'm usually right around 12-15mph. I throttle up on to plane, and then pull back. With strakes, you'll find that you can probably go 12mph plowing through the water with little lift, or you can go the exact same speed mostly on plane if you start by overshooting your speed and then settling back. I don't know about your setup specifically, but on my boat, it will hold mostly on plane down to about 12-15 if I get it there first. It's a much more comfortable ride at that speed if the boat is mostly on plane. Your mileage will vary. The third pontoon really helps with buoyancy and lift. If you don't have a third pontoon, then experimentation will give you your actual answers.
 
Weight also plays a factor. A two toon 21S with a 115 will plane pretty quick. My 22S with strakes and a 115 jumped onto plane pretty quick with little weight in the boat. 
 
Jeff S,

    I would plane my deck boat in the same fashion, overshoot and throttle back, and it's right where you want it.  Weel, from the responses it sounds like it will perform very nicely.  Thanks to all.   Dan
 
You bring up a good point about strakes that seems to be rarely talked about. Low speed. They are usually part of conversations about top speed. But at low speeds they allow your boat to plane up out of the water at a lower speed/RPM range, which allows you to run more efficiently since you go faster at less RPMs. I will never buy a pontoon without them.

You can see my boat details below. I am on plane at 11 mph.
 
Last edited by a moderator:
Thanks for the discussion on this topic.  BTW, i'm not sure what prop they're going to put on my boat but I will be purchasing a back-up prop too.  Any thoughts what specs it should be?  Again, I have a 21SLX, undersheeting, 115HP Yamaha, and open strakes.  I will be doing limited tubing and even more limited skiing but want to cross the lake quickly if weather turns on me.  The biggest lake on our chain is 1,000 acres.  I probably don't plan on cruising at "cocktail speed" very much and not WOT either.  I like to plane out at a nice speed but not wot.

Thanks
 
I was impressed with Mercury's Spitfire prop. Cheap. Awesome acceleration on my old 115.

If you put your boat details in your signature line, you won't have to input your boat details on each post. And no one will have to ask if you leave something out. It's a very nice forum tool.
 
Thanks for the tip regarding the signature line. I had no idea. I just added my specs. The boat is in and I pay for it next week.
 
When I did my research, lot's of folks suggested the Reliance prop. That's what I did. Happy so far.
 
With the strakes it turns a displacement hull (standard pontoon) into more of a planing hull like a V bottom boat.  With our boat we can give her the juice (doesn't take wide open) and get up on plane then back it down to roughly 3K rpm or a shade under and the boat stays on plane and takes little power to stay there.  The sweet spot for fuel economy seems to be right around 18-20mph in the 3K rpm range....but you can stay up on plane even at a much lower speed with the strakes.  At no wake speed you really don't notice much of a difference with the strakes as you are just putting along.....our normal cruising speed anyway.  
 
You must log in or register to reply here.
Back
Top