Kayak sailing: what a difference a boom makes…

Just to add that my experiences of sailing with a boom mirror Stobbo"s with battens. I found the rolling from jibing was almost impoosible to control without a boom, and I didn't have any problems after fitting one (on an adventure island with the full standard AI sail but without outriggers)

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Simon

Took my boomed Hobie Sport out yesterday on Lake Burley Griffin in fresh winds. Because of the wind direction and constraints on amount of time I had to sail, this pretty much involved running and a little broad reaching down to the central basin of the lake and then about 5 kilometres of working to windward back to the top of the west basin. The sail path (I didn’t peddle at all) and a summary of the wind conditions are shown in the diagram below.

This short unedited video (49 seconds) shows tacking during a lull and then the response to a gust of around 18-20 knots. My head-mounted GoPro was obliging tipped forward by the mainsheet so you can get a complete picture of how the boomed Sport is rigged. Note the Hobie knob on the steering lever - a must-have in my view because it gives much better ‘feel’. WARNING: The video contains scenes of middle aged men in tights. (Necessary, because the sun is still murderous here at noon).

https://www.youtube.com/watch?v=pxjAtSYaP9A


To me, a boomed sail works much better in strong winds than an unboomed one. With an unboomed sail, easing the mainsheet in response to a gust increases the camber of the sail and, hence, the power of the sail just at a time when you want less power! So large mainsheet adjustments are necessary to stay upright; my response to strong gusts was to simply let go completely. At best, an unboomed sail in strong winds makes for very ugly and stressful sailing; at worst, it means too many capsizes for we mere mortal sailors. Whereas with a boomed sail that is properly vanged, the camber of the sail stays the same and only slight mainsheet adjustments are required to de-power or power-up the sail in response to gusts and lulls. In short, a boomed sail de-skills to a considerable extent the art of strong wind sailing.

After extensive testing I am calling this one ‘done and dusted': the addition of the boom has extended the range of winds I can comfortably and efficiently handle. Am still going to install the Falcon sail system (1.3 m2) that includes a stayed carbon fibre mast that pivots down to the deck when the winds get too strong. But will report on that project in a separate topic tentatively called 'Storm sails (or how to conserve your mast receiver)'.

Thanks for the info. I had a TI for one season which was my only sailing experience. (too much for me and my family...lol) When I purchased the TI I also bought a sport for my son.
I purchased the sail kit for the Sport a few years back and have enjoyed sailing up and down the beaches in Destin.
I never really liked the Taco effect. I will give a boom a try.

Bravo!!!!

After my commute back to Berkeley from Chrissy Field with strong tail winds I can really appreciate this!!! Main sheet slamming into my heads etc etc.

Is there a thread or you tube video that goes into how you make this?

OK, I have read this whole thread several times through now, and am starting to install a bamboo boom. With the boom installed would obviously make furling not possible. So what does one do instead if the winds are just too strong?

Good point! If the winds are strong enough to make one want to furl then it would be hard to get to, but I definitely want to make it removable.

I can furl with the boom - that's why the outhaul line is so untidily long - but obviously not as easily as without a boom. First, I have to capture the end of the boom to un-cleat the outhaul line and unclip the boom vang (easy). In combination with the outhaul line, I use an easily-undone soft shackle that holds the clew of the sail close to the boom so it is theoretically possible to have efficient partial furling of the sail. (I haven’t needed to furl yet so maybe I will run into some unforeseen problems in real sailing situations).

In response to Zenyak’s request, I was going to shoot a driveway sailing video last Sunday to show in detail the components of my rigging scheme, but rain (42 millimetres), Sunday-sleepiness and Mother’s Day responsibilities came together in a perfect storm to prevent this. Instead I will post shortly (tonight?) a diagram showing the rigging plan and details of components, including a photo of the all-important connection of the boom to the mast.

Well that was disappointing. On my way back to Berkeley from Crissy field across sf bay. I had strong direct tail winds as usual. Was excited about my new boom, but it became unclipped at the outer corner of the sail while launching so I never really got to try it. I tried many times to reattach it by heading up wind so that the corner of the sail was close to me, but everytime I grabbed it, the sail would catch wind and the boat would start to tip dangerously.

I had to let the sail whip violently with no power in it. Everytime I tried to pull it in the main sheet would start bashing into my head.

On a good note later on with less wind I was able to sail and had the best surfing so far. I was riding down a wave for a long time basically moving at the same speed as the wave! Had experienced this before quite a few times but never rode the same wave for as long before.

In hopes to avoid getting hit by the main sheet I moved it further back to the stern (I'm on a adventure}, but it didn't help. Looking forwards to getting another chance to try the boom again. Any advice about how to rig the main sheet so as to not get hit by it?

Spoken to the guy who makes these sails - the mast is designed to bend and spill air rather than overload the hull.

Here's a simple "boombat" -- an extra sail batten slipped through the foot of the sail with a wire-nut screwed on the end for easy gripping. No sail mod necessary, nothing to hang down and bump your head, Easily removed and stowed in the hull (slips in the hatch) so the sail can be furled. This is about as quick, simple and easy as it gets.

As you'll see from my post(s) earlier in this thread, and also in this thread: http://www.hobiecat.com.au/forums/viewtopic.php?f=11&t=54137&sid=32f73af8db9ba8d65063ac3f2748539d&sid=32f73af8db9ba8d65063ac3f2748539d#p256986, if you attach a lightweight boom to the mast with a Prusik knot, which still allows the mast to rotate, and attach both the clew of the sail and the mainsheet to the boom with Prusik knots, which allows both to slide along the boom when not under tension, then it's easy to have a boom that allows furling without ever needing to remove it

A boom allows you to control the draft of the sail by having it more or less flat, depending on the conditions, so giving finer control than a boombat, but without a vang it won't do a great job of contolling sail shape downwind as the boom will lift, so downwind at least I think a combination of both boom and boombat would be best if possible where the boombat.is angled down toward the stern (such as with the Hobie kayak sail). Unfortunately the bigger Adventure Island sail doesnt have a convenient sleeve for such a boombat...

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Simon

Does the bungee connecting the sail to the downhaul hook on the Hobie Furling Kit have to stay connected to furl the sail? Wondering how the sail can be furled, boom attached, with the bungee connected? With it connected, as the furling, mast, and sail all spin around, the bungee would encounter the jaw slide that the boom attaches to, and wouldn't be able to spin anymore.

Looking to purchase the Falcon Sails boom, but right now the only way I can think to furl the sail would be to unhook the mainsheet, unhook the outhaul, fold the boom up parallel to the mast, and furl the sail around the mast and boom together.

Yes

By attaching the boom to the mast with a Prusik knot, this is not an issue. If it works with a Hobie Adventure Sail, beleive me, it'll work with that relatively tiny Falcon sail. See my post above

You don't need a built-for-purpose boom. The right combination of the right sections of the right diameters of fibreglass telescoping fishing rod sections fixed together with epoxy to stop them telescoping will be fine, attached to the mast/clew/mainsheet with Prusik knots. See my post above

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Simon

Video shows taco-free sailing in gusts approaching 20 knots when running and broad reaching. (Why is it always gusty under bridges?)

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

Yes, I think you are right about over vanging. I went out thinking that twist in the sail in the strong winds could cause air to spill up high on the sail leading to Laser-like death rolls. But my fears were sort of allayed when I saw that air spilling as the mast bent in response to strong wind gusts did not cause stability problems (see around the 5 second mark of the video in my previous post).

The boom vang is surprisingly easy to adjust from the seat of the Sport so I will be a little more adventurous in its use when I next go sailing. Adding a few tell-tales along the leech will help in setting the right twist. Hopefully, a better sail shape will also fix the leech flutter issues evident in the video.

Thanks.