Early planing question

[johnk]

Hi Roger,

I purchased a Bic Techno Formula (267 x 94 cm, 170 L), 70 cm race fin, and a 11.0 Maui Sails Titan rig with adjustable outhaul a few years ago to increase my planing time at my sailing site which is a light wind venue. Overall, I'm pleased with the results and find that I can start planing in ~10 knots of breeze with this setup at my current weight of 185 pounds.

I find there too many times where the board is borderline planing and would greatly appreciate clarification regarding mast base placement and board trim. In marginal planing conditions, should I be moving the mast base aft to improve early planing? I usually trim the board level (side to side), but have read elsewhere that some sailors put the lee side down a bit to get going on wide boards and big fins. What would be the best trim setting to get planing? I am a passive sailor and have not yet learned how to pump the sail to help planing, so any tips here would be great as well.

Thanks in advance,
JohnK

[Roger]

Hi John K,
I'd suggest placing the mast foot fairly far back.
Why?
To get planing in really marginal conditions, you need to get the nose of the board UP to get the necessary for and aft trim to allow the board to jump up over it's own bow wave.
On a true 100 cm wide formula board, placing the mast foot near the back helps with early planing, but creates issues with high speed control once you get up to speed in fully powered conditions and heading downwind probably alot deeper than you (as a recreational sailor) would normally ever go.
You may be able to fin a larger or more powerful fin to get more fin lift sooner (in marginal conditions) to get you planing and keep you planing. The downside is if the wind comes up significantly, you would need to use a smaller fin to regain some control, and the larger fin may limit your top speed slightly.
Again, marginal conditions require special rigs/fins/techniques.
I would use a flat rail to rail triim to get planing, and if you are fully planing, you can use a little bit of
lee rail down trim to head upwind, but be careful as in really marginal conditions, heading very far upwind can drop you back off plane.
Try to get going on a reach or slightly below.
If you head upwind at all, while trying to get your board planing, you will actually diminish the likelyhood that you will plane.
Also, a couple of big pumps on your 11.0 m2 rig should help pop your board onto a plane. If it takes more than 2-3 pumps, chances are there's simply not enough wind.
If your board starts to plane, you can "pump the fin" with your back foot, once you are in the staps, to
help free up your board and increase your speed.
Pumping the fin simply consists of pushing hard (jabbing really) across the top of the board with your back foot.
A wider board would help, but you are already at 94 cms, which should be nearly as good as a full 100 cm wide formula board, but easier to sail and control in powered up sailing.
Hope this helps,
Roger

[johnk]

Thanks Roger. Very much appreciated!

[johnk]

Originally Posted by Roger

A wider board would help, but you are already at 94 cms, which should be nearly as good as a full 100 cm wide formula board, but easier to sail and control in powered up sailing.
Hope this helps,
Roger

Hi Roger,

I saw in another message that you tested the Ultrasonic and wanted to ask your impressions of this board for a progressing sailor. I'm wondering if a lighter weight/more modern board like the Ultrasonic would be an improvement in early planing over my Bic Techno Formula.

Thanks again,
John

[Roger]

Hi John,
Yes the US147 is very easy to sail and it gets going about as fast as any board (bsides a 100 cm wide]
full race formula board) I've ever sailed.
Where you will find one, in the USA, and at what price? those may be the harder questions.
The performnace is definitely there.
Roger

[Sailboarder]

"I'd suggest placing the mast foot fairly far back.
Why?
To get planing in really marginal conditions, you need to get the nose of the board UP to get the necessary for and aft trim to allow the board to jump up over it's own bow wave."

I am a now an advanced beginner and find this counterintuitive. Is it because the bow wave will be further back and bigger, allowing to glide in front of it better when you transition to a plane?

On my longboard, I was using a more front position that allow a faster speed while not planing, hoping the initial speed would help with planing. It is quite faster off the plane that's for sure. The transition to a plane is also smooth. If I understand correctly, I would plane sooner with the mast more to the back, but I would need to kick the board more abruptly to get over the bow wave. Does this makes sense?

[Roger]

Hi Sailboarder,
Ummmm adding in your longboard experience is kinda mixing apples with oranges.
Longboards have a fairly flat rockerline from well forward of the mast track to the tail.
Short boards (and especially wide formula and early planing type boards) have a much different
rockerline with the transition from rocker to flat way back at the front of the front footstaps.
Lots of progressively increasing rocker forward of the footstraps.
So, if you do not get back on the board, and get the nose UP, you will constantly be trying to
get the board planing, with the flatter planing surfaces from the footstraps back actually lower in
the front. So until planing surfaces are inclined higher at the front, the boards nose is out of the water,
and the bow wave has moved back to the rocker transition under the front footstraps, the board will pretty much refuse to plane (negative rake to the planing surfaces).
Longboards are very different in this respect. Some of the transition boards, like the Rio's are a bit of a hybrid in this respect and while they do OK in longboard mode, they do not have the "glide" found in a traditional longboard or something like the Phantoms with the long flat rocker from the mast track to the tail.
Roger

[Sailboarder]

JohnK, I hope you got your answer earlier, because I feel like hijacking your thread.

Roger, this is very interesting, and lightbulbs are now turning on in my head!

I just measured the rocker of my Kona and it seems similar to shortboards. It is flat from the back to the front of the front footstraps. From there, it gets curvier and curvier. This explains why the board is slower than raceboards, while still being maneuvrable. The duck tail also helps for sure.

It also explains a slow plane mode I got stuck on once in a while. The boards reacts as if planing, somewhat fast while not fully released, and water is released in front of the mast base. The negative "rake" was the reason! I will get the weight further back and the nose higher up...

So, it's not a matter of getting a big bow wave, but more a matter of having it at the right spot (indicating a proper flat region rake) before pushing the board forward to ride "down" the bow wave while releasing the board. Even if that last sentence is not perfectly right, I am sure to be on the way of earlier planing!

Thanks!

[Roger]

Hi Sailboarder,
Yes, the Kona has more of a "hybrid" rockerline.
They plane with the nose significantly higher (relative to the water surface) than does a true longboard (with the moslty flat longboard rockerling).
The Kona gives up a bit of ultra light wind (< 7-8 knots) glide to the true longboards (Mistral Equipe,
Fanatic Ultracat, F2 Lightning, etc) for a bit better/earlier planing at >12-14 knots.
Let us know how your new found ideas work out.
I'll be interested to hear.
Roger

[johnk]

Sailboarder, chime in any time.

Originally Posted by Roger

Longboards are very different in this respect. Some of the transition boards, like the Rio's are a bit of a hybrid in this respect and while they do OK in longboard mode, they do not have the "glide" found in a traditional longboard or something like the Phantoms with the long flat rocker from the mast track to the tail.
Roger

Hi Roger,

In an older thread, you had provided a great tip to observe where this rocker transition is by running a string lengthwise down the bottom of the board with weights on either end. I was surprised to see that my Bic Techno Formula was perfectly flat from the mast track to the tail with all of the rocker forward of this point (probably a dated design). Nevertheless, I now understand how the front of this flat section could be negatively inclined (lower in the front than back) and will be adjusting my mast position as well as stance to get this part of the board up. I'm looking forward to putting this to practice over the upcoming weekend.

Thanks again,
John