The Offshore Voyaging Reference Site

V Booms a Great Idea

Pocket Boom, V Boom, Park Avenue Boom, it doesn’t much matter what we call them, these booms are a great idea that should be adopted by a lot more sailors than do.

A great way to simplify sail handling, and make it easy to put on the sail cover, but without the complexity, weight, performance loss, and, yes, dangers of in-mast or in-boom furling systems, and way cheaper, too.

If you are considering an automated mainsail system, do yourself a favour and think long and hard before you pull the trigger and blow a wad of cash.

Instead, fix the slab-reefing system on your boat properly—a good 80% of the slab systems I see are poorly designed and set up—and, then, if you want to take it to the next level, buy a V Boom.

This one from Offshore Spars looks like a nice implementation. I’m guessing it’s a derivative of the brilliantly designed V Booms that Hall Spars used to make.

I wanted one of these in the worst way, but after we got done replacing our cracked aluminum mast, there was no money left.

More on how to decide between in-mast, in-boom, and slab reefing. Yes, there are situations when one of the first two options makes sense…but not that many.

And if you think in-boom systems are easier to use, watch this:

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Alastair Currie

I have seen a similar idea but the shape fabricated from tube along the boom.

George L

see comment above.

I wouldn’t use stainless.

Concerning injury, not sure it matters much what part of the boom hits you – the consequences are horrid no matter what – whether your neck gets broken by the boom, or the brain gets banged up makes very little difference – the outcome is the same

George L

Hi John,

I guess it depends on the circumstances. We ended up setting the boom well above head height for that reason.

However if you consider the striking surface of the boom in the picture at the very top, I don’t think it is any different from that of a 25 or 30 mm pipe. So, if blunting the blow is the objective, perhaps neither should be used and we should stick to the regular shape.

Jeff Totman

I find the idea of V shaped booms or booms with protrusions to be an unnecessary expense/complication, and possibly dangerous in the case of protrusions. A swinging boom has so much inertia that even a pretty innocuous looking bump on the head can have us seeing stars. I’d hate to think of all that inertia getting transferred to a skull via a small surface area rather than spread out over several square inches where a flat sided boom makes contact.

My current boat has a Profurl behind the mast furler that Ive learned to like a lot but my previous boat had slab reefing and a lazy jack setup that made things SO easy, just flake the sail into them, wrap 4 or 5 sail ties around the sail to hold it in place over the boom, lead the lazy jacks forward along the boom and under the reefing hooks to hold them in place and tension them using cam cleat mounted on each side of mast. Then throw your simple, one piece, continuous sail cover over it and secure it in place. So simple and fast that there’s no reason to think of it as a task to avoid. When it’s time to remove sail cover, start at the back and roll or fold it forward so when it’s time to put it back on you can fasten the front part around mast and then unroll it, pull top of sail cover taut and secure to end of boom, then just walk forward along boom tying or clipping bottom of sail cover together. Done.

Svein Hellesø

In addition to the advantages in controlling the sail on top of the boom, there might also been an aerodynamic advantage in that the wider boom acts as an end plate for the main sail reducing pressure spill over from the windward side.

Apparently very important in some cases (Americas Cup etc. where the deck acts as a big endplate), but for a cruising boat maybe mostly a small added bonus.

George L

Hi John

we priced this out in aluminium, it was more than the boom itself and I was not enamored by the look (though you can sleep up there when its really hot and the sail isn’t up. Also it reduces how far you can let out the sheet before the boom hits the shroud

Our solution was to have three bars each on the boom spaced so none would hit the shroud. These are kind of three dimensional – with a support in the center, so nothing will bend. Good old triangles …

The lazyjacks go to the outside of the bars.

Same benefits, cheaper, lighter, no problems.

George L

you can do much more, shapewise, with carbon than with aluminium (which was the option we considered – Sparcraft France) and they look quite good on large yachts, IMO. We didn’t bother carbon for the boom because the weight penalty of an alu boom is much less than that of an alu mast.

point taken.

concerning ugliness etc. we decided this on the basis of drawings and it looked ok to us – ugly did not come to mind, but that’s in the eyes of the beholder. to us the benefits were bigger, light weight and doing the job. I commented concerning the danger above, but we may agree to disagree on that one.