I know one-up is fastest in terms of VMG when racing around buoys. However, we are looking to occasionally sail double-trap under spinnaker for fun (i.e., point higher and get more speed) and are curious whether the boat (Inter 20) is designed to take the loads? I suspect the answer is yes, at least in winds up to 15 kts, but perhaps some folks have valuable advice.... Pertinent settings are mainsheet in very tight, mast rotated 90 degrees, and substantial tension on the diamond wires. Thanks.



Edited by traphappy on Jul 18, 2018 - 04:38 AM.

Wouldn’t the boat just turn over sideways if you had too much power? Not sure the boat would notice a difference in loads compared to just having the main up and being overpowered. I would take the spin any direction if I can hold the boat down. If the wind is light enough that you can actually have the spin out on a beam reach then why not. Assuming it’s flat enough to not just collapse on itself.

Google nacra inter 20 on images.google.com. Lots of pics double trap with spin. We do it on my boat with no issue.

--
Steve
Nacra Inter 20
Okemos Michigan
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Another inter 20 owner....no issues. I will say that when the wind is around 10-12 and 2 can get on the wire and fly a hull with the kite up and boards all the way down, the boat doesn't feel great. Sort of bound up for lack of a better term In 15+ when sailing deeper with 2 on the wire it's completely different.

Double trap kite reaching on the Nacra 20 was a regular occurrence during the Worrell 1000, Tybee 500 and other distance races. I am not the worlds foremost expert on this skillset, as there are many distance racing sailors who are faster in this mode but a lot comes down to helm experience.

A few critical notes:

1) Never ever ever let the mainsheet off in this situation. Strap it down tight. If not, you will snap the mast.

2) You can ease traveler to the hiking strap, possibly a bit further but do so at your own risk.

3) This mode really loads up the rear beam. I have seen these beam bolts pull out. Older boats have been retrofit with bigger stainless backing plates inside the hull in some cases, in others I've seen total boat failure (on a boat with at least 3 Worrell 1000's and 2 Tybee 500's).

4) You probably want to ease your kite halyard or tack line off some depending on the rigging setup.

5) Be prepared to go swimming, helming from the trap in big breeze and waves isn't easy. I recommend a wide stance and you want to use the rear footstrap. We always rigged chicken lines for ocean work as it reduced crew fatigue by orders of magnitude.

Thanks all. Each of the answers were very helpful. My boat, an 05, does not have rear beam reinforcements. That looks like an easy and prudent modification. Also, very good info about the boat feeling bound up in certain scenarios. Good to understand that. Happy sailing!

pull the boards up 1/2 way, and the boat will not feel as bound up. Surprised you haven't broken them yet. We went through a few before we learned that lesson...

What Sam and Mike said...

The Nacra/Inter 20 mast is tough, but I've seen them break in person with the kite up. One of our mantras when pushing downwind is, "protect the stick", so we're always mindful of rotation, cunningham and sheet tension.

Although fun, double trap with the kite really isn't that fast unless you are in just the right performance envelope; wind speed, angle/heading, etc. Like Sam said, we really only do it when we "need" to either because we're tying to carry the kite high (not enough wind to jib reach yet), or it's just that windy and we need the weight to hold the boat down even when going deep.

Regardless, Nacra/Inter 20 or the Nacra 6.0 is probably the best bet.

So.... We did not double-trap with the spin when we went out, but we did something else quite interesting. We hit a sandbar sailing 18 knots (on the speedpuck) with crew and skipper both out on the wire and boards down all the way. Boat stopped instantly, and crew and skipper peter-panned out onto the spin pole. No major damage to the boat, including boards. Perhaps the loads were reduced because we were flung forward, which caused the boat to pitch more. Need to fix the homemade speedpuck bracket and avoid hitting sandbars next time out!



Edited by traphappy on Aug 04, 2018 - 10:15 PM.

trap,

I wouldn't be so sure there isn't damage to the boat. The trunks can take a lot of abuse but they have limits.

-Sam

Yeah Sam, I agree 100% with you. All was well when sailing yesterday, but it would be hard to know if the impact caused any cracking the trunk laminate. In any case, the outcome was far better that I anticipated when we hit.

It's a relatively easy check with some water+tiny bit of soap and some pressure on the hull. A full inspection is also pretty convincing, area to look for on the N20 is the back of the daggerboard well but all trunks can start leaking at the bottom and top where they meet the hull. Repairs aren't easy but they are do-able.