BR20 Sail & Rigging Modifications

There is a wide range of possible modifications to the BR20 sail plan and rigging, some designed to make the boat easier to handle but many aimed at improving the BR20’s already excellent sailing performance. This article is an attempted compendium of most of the known modifications, gleaned from contributions to the SBA forum.

Working backwards from the bows:


Plank bowsprit

This solid piece of wood is bolted to the foredeck and secured to the towing eye on the stem plate with one or even two bobstays to counteract vertical forces from whatever sails are attached to it.  It can be further secured with bowsprit shrouds attached to D rings on the gunwales to counteract lateral forces from sudden gusts.

There are two possible uses for a plank bowsprit:

  • As a more solid substitute for the standard carbon spinnaker pole, from which can be flown the asymmetric spinnaker and/or a flying jib
  • As the anchor point for the tack of a conventional jib, for those who prefer this to the self-tacking jib arrangement

Hirundo’ with medium bowsprit and conventional jib

Medium plank bowsprit on a BRe

Long plank bowsprit on a BR20 with conventional and flying jibs

Conventional jib

The self-tacking jib is excellent for short tacking, when sailing solo and for goose-winging downwind.  However, some prefer to have more control over the shape of the jib to windward, particularly in light winds.  A conventionally-sheeted jib can provide this and in addition, because it is not constrained by the jib boom, it can be a bit longer-footed to provide partial overlap with the mainsail, thus potentially generating more of a slot effect and more power to windward. It can be flown from a long plank bowsprit as shown above or from a shorter (and less intrusive) bowsprit as shown below.

Conventional jib flown off short bowsprit

Anyone considering these changes should be aware that the forces on the jib sheets are much stronger than with the self-tacking jib.  The jib sheets will need to be attended to (with gloves on) at every tack.  The jib sheets also have a tendency to foul the lower horn cleat on the front of the mast when going about.  This can be remedied by installing cleat boots over the offending cleat.  On the plus side, a conventional jib makes heaving to a bit easier.

Convert jib boom into bowsprit or even extended bowsprit

As an alternative to the above arrangements and working with the existing standard self-tacking jib arrangement, it is possible to some extent to have your cake and eat it.  Attach an endless loop strop to a strong point on the forward part of the mast near the base, loop this under the aft end of the jib boom and you have a slightly wobbly fixed bowsprit.  This then gives the opportunity, with a set of jib sheets attached to the jib clew where the outhaul normally is, to play with the shape of the jib independently of forestay tension. Some have even extended their jib boom forwards so that an asymmetric can be flown off the end of it instead of from the carbon spinnaker boom.

SeaRaider with carbon fibre extended jib boom

Reinforced jib boom

There is a school of thought that says that the standard wooden jib boom could do with a bit of strengthening.  It does tend to bend a bit when heading into strong winds, which causes sagging in the leeward shroud.  The argument goes that this sag spoils the trim of both the jib and the mainsail.

The suggested solution is a carbon or reinforced wooden jib boom.  The former can be made up from a section of windsurf mast, one piece inserted inside another and bonded in place with Sikaflex. The SeaRaider photo above is a slightly extended version of this – the extension probably needs to be longer if an asymmetric is to be flown from the end of it .

Another use for the spinnaker halyard

For those that would like to control the leech of their self-tacking jib a little better, it is possible to attach your spinnaker halyard (if you have one) to the aft end of the jib boom and hoist it upwards, so that the leech is independent of forestay tension.  Useful for controlling jib shape in light winds, it can sometimes give rise to a slight reluctance for the self-tacker to tack but otherwise seems to work quite well.

Flying jib

A flying jib is an extra foresail that can be hanked on to the end of the carbon spinnaker pole or plank bowsprit, forward of whatever jib you are flying (conventional or self-tacking).  This sail is useful in light winds on any reach (except perhaps a close one) and can really add to forward motion.  Unlike an asymmetric spinnaker, it only has a small area (about 3m2) and is much easier to control single-handed.  If you are going to fly two foresails at once, you will need two sets of sheets, which means that you will need to install additional fairleads and camcleats to supplement those installed midships for the self-tacking jib.  The best place for the extra camcleats is just astern of your forward oarlock bases (if you have them), or about 18” astern of the shroud plates.

Flying jib being flown off the spinnaker bowsprit


Tweaks to the asymmetric

The asymmetric can be a bit of a beast to control in gusts – anyone hanging on to the spinnaker sheets needs to wear gloves.  An extra help is to attach ratchet blocks on strops through the middle of the midships oarlock bases, using a cow hitch.  The spinnaker sheets can still be released in a hurry but the ratchet blocks mean that it is not necessary to hang on grimly to the sheets at all times, merely to keep them under a bit of tension.

Ratchet block on a strop

The standard arrangement for the asymmetric spinnaker’s tack is for it to be hanked on to a non-adjustable bobstay that is attached through the end of the spinnaker pole to the towing eye on the stem plate.  You will have a bit more control over this sail (including a second method of depowering it in addition to letting go the sheets) if you have an adjustable tack line.  This can be brought back to a cleat in the cockpit through the middle of the spinnaker pole or, if you have a plank bowsprit, through the now-redundant spinnaker pole tube.  For optimal shape of the asymmetric, the tack line should be progressively eased as you point further downwind. Of course, if you adopt this arrangement you will need a separate bobstay.

Tweaks to jib halyard

The standard jib halyard is lead through a fiddle block at the masthead down to the base of the mast.  If you want to add a bit of mechanical advantage in raising and lowering the mast, replace the fiddle block with a double block with becket and add a second single block with its becket attached to the top of the furler swivel.  Correctly rigged, they make it very much easier to raise the mast past 45 degrees and to tension the forestay.  Lowering the mast is also a lot more controlled.  The existing halyard is just about long enough to cope with the extra journey through the blocks.

Double blocks at the masthead, giving mechanical advantage to the main halyard



The suggestions below are based on having the cheaper gunter-rigged mainsail, with carbon yard and wooden mast.  If you have a one-piece carbon mast and roached mainsail (standard on the BRe and an option on the BR20), many of these suggestions are redundant.

Stiffer yard

The standard yard supplied with the gunter-rigged BR20 does a pretty good job.  When beating in strong winds however, it tends to bend a bit, causing the mainsail to sag astern and to leeward and to spill wind.  The solution is to replace it with the stiffest yard that you can find (or afford).  A standard measure of carbon mast stiffness is the IMCS scale.  The standard BR20 yard has an IMCS of something less that 30.  Some high carbon windsurf masts go as high as 38 or 40.  By getting a long one (eg 5.8m) and cutting it to size so that you are using the lower section, the IMCS rises further.  If you then cover it in a unidirectional sheath, the IMCS rises still further but at the expense of weight aloft.

Tweaks to the yard

The standard yard on my BR20 (hull number 59) is secured to the main halyard with a arrangement that reaches around the back of the yard, through a cut down bullseye fairlead and then clips on to itself in front of the yard.  There is one of these bullseye fairleads for each of the three possible yard positions (unreefed, one reef, two reefs).  A better alternative is drill a hole through the middle of the yard at the unreefed position, threading the halyard aftwards through the hole and securing it with a figure of eight knot.  This stays semi-permanently in position and helps to provide a snugger fit for the yard against the aft face of the mainmast when unreefed.  The hole through the yard should be as small as is consistent with fitting the halyard through it, and both reinforced and waterproofed.  Reefing is achieved by installing permanent strops on the aft face of the yard, at reef positions one and two.  These strops tie around the main halyard and the front of the yard when reefing, stopping the yard from being raised any further than the point at which the strop is tied.  This saves time hitching and unhitching and makes reefing a bit quicker.

An alternative for at least one reefing position is to have a dedicated slab reefing downhaul line permanently attached to the yard at a reefed position, threaded through the same dumb sheave at the mast top as the main halyard, and attached to the same cleat at the mast base.  When reefing, lower the yard on the main halyard and haul in the reefing downhaul, thus securing the yard against the mast at its reefed position.  This could be a worthwhile modification if you have a smaller cruising mainsail (see below) with only one set of reefing points.

Double topping lift

This modification, which I strongly recommend despite the fact that it increases windage, is for much easier handling of the mainsail rather than for improved sailing performance.  It is dealt with in detail in the library article “Keeping the BR20 mainsail tidy” in the section “Towing, Sailing & Rowing”.  A significantly longer downhaul track on the aft of the mast base obviates the need to detach the mainsail tack every time the mainsail is tidied away.

Smaller mainsail

There is a school of thought that says that for cruising at sea, the high aspect gunter rig may provide a larger mainsail area than is strictly necessary and may deter owners (particularly when sailing solo) from putting to sea in stronger winds.  The solution?  A cut down mainsail with a smaller area, which allows for a shorter yard and, if the foot of the sail is also shorter, a reduced sprit boom as well.  If the luff is short enough, the yard can be dispensed with altogether.  When installed, it would be about the same size as sailing with a permanent first reef in the standard main.  Such a sail could be battened to improve efficiency and ought to have at least one reefing point for when the wind really blows.  The modest drop in sailing performance from the smaller sail area is more than compensated for by greater ease of handling of the mainsail and its associated spars.

Junk rig

Always a possibility.  See the library article on junk rig in the “Boat Information and Design” section.

Other tweaks to the mainsail

When beating in light winds, you may point a bit higher by pulling the mainsheet inboard.  A simple “traveller” can help.  This can be made with a wide-mouthed trapeze ring and a few bits of string.  For the traveller to work, you need a spinnaker sheet block on an endless loop each side, supplied as standard with the asymmetric by the boatyard, as in the picture below. The small white cord is tied to the sprit boom to stop the ring from slipping down and interfering with the mainsheet blocks.  The mainsheet is inserted through the trapeze ring and the other line pulled through the windward spinnaker block.  When not in use, it can be let go from the spinnaker block and the whole thing just dangles harmlessly, suspended from the boom.

A simple traveller for upwind work in light airs

My BR20 was supplied with a hemp lookalike mainsheet that was a bit rough on the hands.  There was a single block and becket attached to the sprit boom and a fiddle block camcleat with (unused) becket, shackled to the U bolt in the cockpit sole.  This arrangement gave a threefold mechanical advantage.  I replaced the mainsheet with something easier on the hands and replaced the single block and becket with a fiddle block attached to the sprit boom.  I now have a fourfold mechanical advantage, a mainsheet that is easier to tweak and adjust and one that is kinder on the hands.

It is possible to set up a self-tensioning mainsail outhaul by attaching the upper mainsheet block to a revised outhaul on the sprit boom rather than directly to the sprit boom itself.  As the mainsheet comes under increasing tension with strengthening winds, it pulls down on the outhaul, thus putting it under greater tension and flattening the mainsail.

Self-tensioning outhaul arrangement (mainsheet clipped to outhaul instead of to strop on boom).  Given the forces exerted by the mainsheet, a stronger outhaul line than the one shown here is advised.



There is an alternative mizzen sheeting arrangement, shown in the photo below.  It pulls the mizzen boom down under tension, which may improve its shape and stop the leech flapping in strong winds. A possible disadvantage, yet to be proved one way or another, is that it may not be quite so easy to back the mizzen when going about or when trying to sail backwards, which can be useful for manoeuvring.  On the other hand, it should impede the mizzen from blowing through 180 degrees if one of the sheet ends slips from its cleat when sailing downwind.

Alternative central mizzen sheeting arrangement with the sprit boom in its usual position

Another view of the central mizzen sheeting arrangement

This central sheeting arrangement can also be used with the boom horizontal along the foot of the sail, as in the photo below.

Alternative mizzen sheeting and boom arrangements in action

For really light wind sailing on a beam reach, it might be possible to use a mizzen staysail, rigged as in the diagram below.  Advantages would be relative ease of handling when solo (compared to an asymmetric) and it would look good in a traditional sort of way.  To rig it properly, the mizzen mast bracket and mizzen mast itself would probably need to be reinforced and additional cleats and fairleads installed.  One day…….

Mizzen staysail diagram




If you don’t already have them, telltales are worth attaching to all sails, but especially the jib.  See the library article “Sail trim and telltales for a BR20” in the section “Towing, Sailing & Rowing”


Possible uses for this high tech material, with low weight and low stretch include:

  • Replacing the jib and main halyards (so called “Cruising Dyneema” is a useful halfway house)
  • Replacement for the stainless steel shrouds
  • Plank bowsprit bobstay and shrouds
  • Lacing the mainsail on to the yard
  • Soft shackles to replace some of the stainless steel variety

The disadvantage of these materials are that they are slippery and do not always hold knots very well.  Splicing is to be preferred to knotting wherever possible.


It is probably better to try the simple modifications first – those that are cheap to implement and which do not involve drilling holes in the boat. Recommended are installing telltales; using the spinnaker halyard to ease leech tension on the self-tacking jib, especially in light winds; using a “traveller” to bring the mainsheet to windward in light winds; and using ratchet blocks to control the spinnaker sheets and to save your hands and arms from too much strain.  Although it does involve a bit of drilling, installing a double topping lift (if you have a gunter rig) is highly recommended for better control over the mainsail and generally making life easier.

Graham W   March 2013