Planing speed?

[Ironworker]

Gents,

I know every boat is different but what is your planing speed?

I'm considering some hull modifications to lower my planing speed as much as possible along with oversized trim tabs. I need to plane my boat at 15 kts or less.

[PeterPalmieri]

With my 454s and trim tabs, I was able to stay on plane at about 13.5 kts. I never really tested it, so I guess a lot of conditions could vary that. For the bow to drop down it was a bit faster.

[bob lico]

think !!!!!!when you are in a kayak or a canoe and you want to slow down or stop you simply put the paddle in the water flat side of paddle down and the kayak slows down thus the same thing you are doing with those trim tabs to keep you on plane ,it is going to coat you fuel economy.

[Tony Meola]

Rick

With the 270 Cummins I plane at around 12 knots. I don't think you are going to have an issue planning off less then 15 knots. Unless you have a bunch of close friends with you who are heavy weights. But I think you will still find, it easy to plane off. Heck, with the Big blocks, 6 guys, 300lbs of ice and 50 gallons of extra fuel, we still use to plane off under 15 knots.

Why is 15 knot planning speed so important?

[Carl]

think !!!!!!when you are in a kayak or a canoe and you want to slow down or stop you simply put the paddle in the water flat side of paddle down and the kayak slows down thus the same thing you are doing with those trim tabs to keep you on plane ,it is going to coat you fuel economy.

I am going way out of my element here, I think we have a few pilots who can correct my thought process.


Yes, adding tab can act like brakes...

AND I think tabs can also act like Flaps on the wing of a plane. Flaps slow a plane while also increasing lift, allowing the plane to fly at a slower speed than without. Slower speeds for take off, landings or short runways seems like a good thing.
Bringing that thought over to a boat I think a tab, as you said Bob, can add some break. However, the extra lift created by adding tab allows the boat to plane at a slower speed.

Planing at a slower speed can be beneficial at times.



Limited visibility when you can only go as fast as I can see has had me run those slow slow cruising speeds. Think early morning, dusk, well lit nights, fog, debris.

Fast troll...I think wahoo is in and around that speed.

A cruise to nowhere

Some sea Conditions


To your question- without tabs, my boat when gas used to be on plane at 15mph.

[Ironworker]

Rick

With the 270 Cummins I plane at around 12 knots. I don't think you are going to have an issue planning off less then 15 knots. Unless you have a bunch of close friends with you who are heavy weights. But I think you will still find, it easy to plane off. Heck, with the Big blocks, 6 guys, 300lbs of ice and 50 gallons of extra fuel, we still use to plane off under 15 knots.

Why is 15 knot planning speed so important?

I do a lot of high speed trolling for wahoo. My optimum speed is 17 kts on the button. 15 kts is the low end and 20 kts is the high end of the range I prefer to troll at.

I've looked a lot at the photos of John Cranston's boat. He has spray rails installed but I have to think they would also serve the purpose of providing additional lift as well to get the boat on plane quicker.

Adding these to my boat will add a couple of days but now is the time to do it if I make the decision to do so. I still have some more research to do before adding them.

[Ironworker]

Bob,

No doubt high speed trolling is a fuel burner but extremely effective fishing technique.

[bob lico]

i am surprised you live in NJ. I have fished for wahoo as a designated species or know anybody who does .just not that many wahoo around to bypass tuna and high speed troll for wahoo and as of lately wahoo are hitting the side trackers in the spread at 5 to 6 knots trolling for tuna.the biggest problem is landing a wahoo with the side tracker not really the best lures for pulling in a speedster. carl my trim tab issue in this case was fuel economy i have never cruised at 13 knots in 20 years with my boat.

[Carl]

carl my trim tab issue in this case was fuel economy i have never cruised at 13 knots in 20 years with my boat.

Yeah- I’m sorry to hear that Bob, but if you ever want to cruise at a lovely calm 13 knots I can hook you up with a sweet set of trim tabs….





Kidding…
You know I cannot resist a Trim Tab jest with you Bob. I know they do not fit your boating needs.

[bob lico]

i gave away four pair and have one left if you need them!!! and BTW a airplane and a boat are no comparison ,a plane has air above and below but in a 31 Bertram the idea is to get air between the strakes for lift.aerodynamics is a hell of a lot easier to play with than hydrodynamics

[Ironworker]

i am surprised you live in NJ.

Bob,

I live in SC and S. Florida. The bulk of my offshore fishing is in the Bahamas, N. Eleuthera primarily. I have year round YF tuna 6 miles from dock. I catch the wahoo on the way to the tuna fishing

[Tony Meola]

Rick

I paid close attention to when I plane off. My Bimini top is off the boat right now, but that has a 2 knot effect on the boat when it is up.

I was starting to plane off at 10 knots and at 11 knots was clearly on a plane. Add my top and figure I will still plane at the same speed but at a slightly higher RPMto get there. Planning speed should not matter, but the RPM's will change depending on how much weight you are carrying.

I have found that once you are up on a plane, she doesn't seem to care how much weight you carry. If 23 knots is 2200 RPM's then it still seems to 23 Knots at that 2200 RPM's.

It just seems she works a little harder to get up when the weight and drag increase, then after that she is up and moving.

[Ironworker]

Thanks much for that info Tony.

I'm going to add some tabs just in case while she is on the hard.