Do booms have to fit "In the Box" too

I have been a little confused by reading certain statements in a number of discussions here, and on the Yahoo Footy group, that suggest that with the Footy in the measurement box, the booms must also fit in the box, and they can’t swing out over the gunwhale over the side of the box?

Rule B.2
The following may project above the top of the measurement box: sail(s), mast, spars, rigging, aerial, associated fittings.

To me that means if the deck of the boat is even with measurement box, then the booms can swing out over the sides. Otherwise, from the pictures I’ve seen, they’d all be in trouble, because all those booms must be 6+ inches long.



Isn’t a boom considered a type of spar?

That’s how I see it.

The booms are part of the support structure, and so they can extend (project) out of the box. Otherwise, the booms would have to be about 3 inches or less, and just about any size sail would have high-aspect proportions.


ERS F.1.2 Spar

The main structural part(s) of the rig, to, or from, which sails are attached and/or supported.

ERS F.9.1 Boom

The spar, its rigging, fittings and any corrector weights, but excluding sheets , sheet blocks and kicking strap/strut arrangement

Thus booms, being spars, can indeed project above the measurement box as provided in Rule B2.


Anybody ever try a 300mm boom on a 150mm mast? :stuck_out_tongue:

can I also take that to mean it can also extend over the side of the box? That’s the confusing part.


Here’s the clarification on this point that is posted in the rules section of the Footy website:

“The word ‘above’ means ‘above and beyond’. Rig etc. components can extend aft of the box, forward of the box or out sideways from the box – so long as they are above the upper horizontal plane of the box.”

I think the source of any confusion might be the discussion of boats built on the vertical diagonals of the box. While it’s not hard to develop a hull that fits diagonally within the box, getting the rig to work within the box constraints on a diagonal hull is tricky.


booms may be completely in the box,completely outside of the box,or both in and out of the box.
Your booms should be able to rotate from fully in to fully out to check for compliance at any angle.

OK, maybe I’ve got it straight now.

If the boat and the booms are below the top of the box, then the booms have to be short enough not to touch the side when they swing out. Conversely, if the booms are totally out the top if the box, then they can be any length.

The mention of ‘compliance’ again confuses things. After reading the rules document again, there is no mention of how booms need to comply with anything. So If you can get the deck of the boat even with the top of the box, you shouldn’t have to worry about length of the booms. The main boom on the blue Sky project seems to be what people mean by 'compliance?"


Okay, here is a more complicated question. Angus mentioned canting rigs and canting keels on another recent Footy thread. Assuming the the shifting ballast aspect of the canting keel is illegal, does a canting rig constitute shifting ballast as well? If it does not and is legal (assuming you could figure out how to control the canting feature with the two servo restriction), would the rig’s relationship to the box be considered vertically only or in the canted position as well?
The canted position would more than likely mean that the booms and sails would be tough to make comply. However, the vertical position is, in effect, averaging the canted rig’s extreme positions. There are several convincing arguments for each method. This is a hypothetical of course, but an interesting question none the less.

I haven’t looked up the ERS, but from memory I think that the answers to that one are disressingly simple.

The function of the canting riig is not primarily to affect stability. Therefore it does not constitute moveable ballast.

In practice, the box is not likely to be a problem - so long as the rig is confined by stops (on sheets, among other things) to positions that will actually be used saling (e.g. very free sheets can high cant cannot be combined). However, the level of complexit of the thing is mind-blowing. I thin I’ll go off and ask nice nurse to bring me my nice pink pills!

i have a canting rig .the bottom of the mast is a ball joint on the deck!!!
i am using the method used for rc landyachts.I was wondering if it is legal or not
can i have a one word answer please not a computer full of emails like a certain other forum at moment.

A one word answer might be a little differcult.
Perhaps a picture of the yacht in question in the mearsurment box with the rig both centred and canted,sheets in and out etc may help.

at moment have not got a box as only me around here with a footy. i think i might have to build a box. Canted in everything is clear of deck so no problem.canted out the loose rigging on the downwind side may touch top of box depending on amount of wind in the sail