another boom experiment

You always have to be careful about thinking (and saying) that some modification you did is faster without taking any real measurements and under what conditions the measurements were taken.

However.. I have tried the boom (rev 2 - top of a 100% carbon very light and stiff windsurfing mast) several times on a Denver lake with a lot of racing. Both times I have had the pedal drive in the rear ane the plug in the front. So my "data" is from sailing with these other types of boats. Sometimes the other guys were in an actual race, somethings just out sailing but Im pretty sure that when the little plastic Hobie starts to pass them, it ends up an unofficial drag race.

In light winds, Im always fast because I pedal.. so that doesnt really count (but that is the way I enjoy using this boat - I didnt spend about 1K on the pedals to not use them). When the wind is enough for boat speeds up over say 4 mph, I have been passing a J22, C30, P21 and P23 keel boats in about any wind or angle. When the wind picks up and I start getting speeds in the 7 to 8 mph range, Im usually considerably faster.

However, this lake has a fleet of Lasers and Lightnings. I can keep up with these boat but I think if I entered one of their races, I would not win. But.. I can still sail with them. I used the boom in the whisker pole mode for presenting max area for downwind and think I was at least keeping up with the Lightning using spinnakers deep downwind.

So.. Im liking the boom. What Im missing in my test is trying the same sailing without the boom but I know in the past that I could not keep up with a well sailed Laser. No doubt the boom used as a whisker pole is faster down wind. Boom adds almost no setup or takedown time and with the outhaul release cleat (see the video a few post back) that allows the boom to be easily connected or disconnected, I still get the easy to use high wind range made possible by the easy reefing on the single sail.

I sail every week with lasers and others (running a course on the lake...... so real sailing and no pedals):
- upwind I always loose (their angel is way better), can't even get close (and I have a Jib, so a bit better angle already)
- downwind... light winds ok (i pull it to the ama), stronger winds.....a laser planes (shoots past you)
- Strong winds...... they struggle to not flip over, you might win (i can still drink coffee .....lol)
- Tacking at the bouys.....I loose a lot of time (no pedals), laser is 2 seconds and done)
- Reaching I am a bit faster but not all all reach angels

Downwind speed with the surfsail (mounted the mast): I am faster (tested with the laser, no gps data)

Your boom setup:
- really smart setup (like it), I am sure it will be faster downwind and have more saling power on reach (a bit better to control)
- the AI/TI just has a really bad upwind angle...... that's why I started experimenting with the surf sail (used the mast as stub)

In real life sailing (competition): it can not compete at all, mainly because off the upwind angle.

I took some video to show the leach tension and twist adjustments of what Ive been playing with. Hopefully you can see the tell tails and the flow in the first part of the video. I think the extra control does allow getting both tell tails to flow backwards more often.

https://www.youtube.com/watch?v=vz7RecRGMmk

Later in the video I had replaced the mirage drive with a plug (first time ever) and it was fun just sailing but the TI sure does take a lot longer to get around a tack if you dont peddal. In the later part of the video, I was doing in 8 plus mph range, sometimes over 10 and there was another TI out at the same time with two people on the boat - one in the back seat and the other out on the tramp. Both TI's were faster than the J22 keel boat who drag raced with us but i think I might have been slightly faster. However the other TI had both mirage drives in place and they were coming out of the turns way faster using the pedals.

At the end of the day, both TI's beached in about the same spot and the other TI was piloted by a couple ladies who worked together and one of them had been a completely addicted windsurfer "back in the day" in the Denver area which I had in common with her. A very pleasant visit finished off a great sailing day.

Hi walt. I haven't been on the site for a while so I was shocked to see my old video still being used. Bought back some great memories in fact of my 1st AI purchase about 10 years ago. Using a Stauff hydraulic bracket, and a collapsible tent pole, that FlexiBoom mod was the 1st and one of the best mods I ever made. Comments were made when I posted the thread that doenwind I could over power and pitchpole but I still use that same design today and so far I've never had an incident. Simple, inexpensive and effective. The speed difference can be seen better here.....
https://www.youtube.com/watch?v=LO9I-tR3I1E

Best of luck with your design walt. You're certainly getting some speed out of the TI.

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Don't take life too seriously................it ain't permanent.

Slaughter, Cool!!!

Ive been playing more with the windsurfing mast boom but cant use it when I have a front seat passenger. But.. had a wild day this weekend with my wife in the front seat in some good wind at 8600 ft elevation in Colorado. I still used that barber hauler loop setup and think it overall helps.

The TI is a great boat for this high mountain sailing.

https://youtu.be/Qb36UJvC2Fc

Another boom video from this summer in Colorado

https://youtu.be/3SFG1hcuW1w

Hi

Rather than start a new 'boom' thread, I thought I'd add my thoughts here.

My original boom solution on my AI in 2015 was similar to Walt's, except that it was more basic and allowed furling: https://www.hobie.com/forums/viewtopic.php?f=32&t=54212

I used Prusik loops to attach the (fishing pole blank) sprit boom to the base of the mast, to attach the main sheet pulley to the boom, and to attach the clew to the boom. This meant no tools were needed, and that I could slide the clew down the boom to allow furling with the boom attached (Prusik knot at mast base allows the mast to rotate while the boom does not).

In its last iteration also routed the mainsheet along the boom before coming down to a pulley on a traveler (mounted on the forward cross bar) then going back to the helm. This created a sort of vang effect that helped keep the boom-end down in downwind conditions.

However, the boom still lifted a bit too much for my liking, and as I sail my AI as a monohull, an aka mounted vang wasn't an option. I also didn't like the fact that I couldn't furl the sail downwind without retracting it, not always possible in challenging conditions

Fusioneng's twin boom idea mentioned earlier in this thread appeals, with the front of the curved booms being held by a rope suspended from a mast topper to allow furling, but I wanted something easier to fabricate, so after I saw Sidney Herreshoff's 1934 Amphicraft arrangement (https://3.bp.blogspot.com/-QGoO-KWjUpg/WHgXNlp078I/AAAAAAAAT1A/kmPnSrhQbKcST29Su1SNcQDco2_MvDGwwCLcB/s1600/Amphicraft%2BKent%2B1.jpg I decided to copy it, but without the two horizontal ropes locating the crossbar to the boom (so I can still furl the sail)

Here's the result (finished yesterday):
https://youtube.com/shorts/Srye_9GeUpw?feature=share


I've used fishing pole blanks again for the crossbar and booms, and used the fishing pole alloy screw-in end-plugs to mount short lengths of cord to join the boom ends together and join the crossbar to the booms. The two vertical ropes at the ends of the front of the booms lead down to a single carabineer on a loop at the mast base that allows mast rotation, while I used the Hobie spinnaker mast topper to attach the top ends of the ropes clear (to clear the sail.)

With the 1m crossbar keeping the booms well apart, I don't seem to need Herreshoff's two horizontal ropes locating the crossbar to the boom side to side to stop the sail touching the booms (or the bars used to the same effect on the Fulcrum Speedworks foiling UFO catamaran)

I really like the fact that I will still be able to furl and unfurl the sail downwind without having to bring the mast back to the cockpit (I've used a 2:1 pully set up to maintain clew tension): https://youtube.com/shorts/sQP-ls3GKbs?feature=share

Hopefully we'll have good weather tomorrow so I can try it out

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Simon

In case anyone is interested, here is the follow up to my twin boom experiment after sea trials
It was quite hard to set up in terms of getting the right sheeting angles and sheeting reduction ratios, but I'm happy with the final result.
The advantages over my original simple sprit boom are
1) It's self vanging - most noticeable downwind or on a broad reach where I have a bit more sail control
2) I can furl or unfurl it without having to loosen any Prusik knots (on the old sprit boom), which means I can quickly furl it on any point of the sail without having to pull the sail in to the centre of the boat (a big safety plus for me)
3) The 2:1 mainsheet pulley arrangement makes it easier to control the sail

Leech tension is OK but could be a bit better, but it's better than the boomless standard set up
I found it hard to get enough outhaul tension and in the end went for a 3:1 outhaul pulley arrangement to help with this, but I still end up pulling on the furler to get a bit of extra tension

The only thing I'm not that happy with is that I often need to give the sail a bit of a tug to unfurl fully

There's a video here https://youtu.be/6kpU-hxItHs showing the final set up (with apologies for the wind noise)

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Simon