Fwd: What the new ILCA4 MkII means for your rigging
Al Sargent
From: Max at Southeast Sailboats <southeast...@substack.com>
Date: Sun, May 10, 2026 at 8:37 AM
Subject: What the new ILCA4 MkII means for your rigging
To: <alsa...@gmail.com>
What the new ILCA4 MkII means for your riggingMake sure your rigging is optimised for the new ILCA4 sail
IntroductionThe ILCA4 MkII sail is now being used by sailors in training ahead of it being made class legal in a few months time. Based on initial feedback from customers whose children have just started using the new sail, I thought it would be a good idea to explain some of the dimensional differences between the old and new ILCA4 sails, and what it means for your control line systems. Note that the following all refer to Southeast Sailboats control line systems/configurations. Cunningham (downhaul)The new MkII sail is made from much stiffer cloth, and, as ILCA acknowledges “sailors may benefit from higher Cunningham purchase ratios to fully access the sail’s depower range”. Early feedback from sailors confirms this. Even on the old sail, many sailors were using 8:1 purchase systems, and with the MkII sail they are now finding it difficult to pull on enough Cunningham. Will 10:1 systems be needed? On the ILCA7 sail, some masters sailors have found benefit of moving to 10:1 systems, especially when sails are new. Note that the downside of 10:1 systems is the increased control line length in the cockpit and as sailors have found on the ILCA7, once sails are older and stretched, a 10:1 system can bottom out if the primary assembly is too long (as a result 10:1 systems have a slightly shorter primary). The luff of the new MkII sail is shorter (4032mm v 4085mm) meaning that the tack grommet position on the new sail is approximately 5cm higher up.
Photo 1 - Old sail underneath with the new MkII sail on topTherefore line lengths ideally need changing, in much the same way as for the differences between the ILCA6/old ILCA7 sail and the ILCA7 MkII sail. The primary line assembly needs lengthening by approximately 10cm (4 inches) to compensate for the additional 5cm up/5cm back down. There are two solutions to this:
OuthaulComparing the old versus new MkII sails shows that the clew grommet is slightly further aft, with the difference seemingly a bit more than the ILCA drawing would infer (2480mm v 2487mm).
Photo 2 - Old sail this time on top with the new MkII sail behindAs a result, depending upon your outhaul system configuration, this may also need adjusting as there is a risk of the outhaul floating block (the one that is fitted between the thin primary line and control line) ‘bottoming out’ (getting too close to the other block). Whether your system will need adjusting depends upon what type of system you have. Top of boom systems may bottom out as shown in the photo below.
Photo 3 - Middle blocks are just a bit too closeThe best and simplest solution is to shorten the length of the strop that is used to attach the block to the boom cleat. This will increase the distance between the blocks when the outhaul is at the tightest setting. Front of boom systems may also bottom out. The best solution here is to shorten the length of the primary line. Side of boom systems have a greater distance between the floating block and the block that sits mid boom, and should still be OK. KickerThe kicker (vang) seems unaffected by the new sail. However, as with all minor variations between hulls, sails, and spars (position of kicker attachment points on both the mast and boom), occasionally the kicker/vang primary line length may have to be adjusted. SummaryAs I get more feedback from sailors I will keep this post updated. Although retired, between events/travelling etc., I do have some capacity to help with amending any Southeast Sailboats ILCA4 rigging if needed. You can contact me at m...@southeastsailboats.co.uk Rigging Matters newsletter from Southeast Sailboats
© 2026 Max Hunt
|
