Sheeting angles and sailing higher

My friend and sailmaker Luis Gianotti from LG Sails was generous to share a very insightful article about headsail sheeting angles from April 1997 issue of "Sailing World" titled "Sailing faster and higher by changing your sheeting angle".

I can't share the article itself due to copyright reasons but the gist of it is that one of the biggest improvements one can make to their performance and pointing ability is to change the sheeting angle of their headsail.

The sheeting angle is determined by the length and position of the jib track, in order to calculate the sheeting angle Luis made a simple spreadsheet, which requires several rig dimensions:

• Distance from deck to headsail halyard block (I)
• Distance from deck to lower spreader (S1H)
• Distance from deck to upper spreader (S2H)
• Distance from centerline to chainplate (rigging base B-2)
• Lower spreader length (S1W)
• Upper spreader length (S2W)
• Distance from forestay to jib track (TRK aft)
• Distance from centerline to jib track (TRK out)

Most boats have sheeting angle in the range of 7.5-10 degrees, 22-25 degrees at lower spreader and 29-34 degrees at upper spreader. The lower the sheeting angle(s), the better the pointing ability of the boat, particularly in light air and calm seas. An Excel spreadsheet with formulas to calculate the sheeting angles is located here and has the data from Southern Cross. As you can see the sheeting angle on my rig is 8.77 degrees, which is somewhere in the middle - not great but not terrible either.

Depending on one's specific case, abilities and risk tolerance the options are to live with it, install a barber hauler or change the rig - move the track, install another track and/or shorten the spreaders. In my opinion making radical changes to the rigging is an expensive proposition which involves shortening spreaders and shrouds and carries a lot of unknowns and risks (including rigging failure), may impact ability to tune the mast, it hard to reverse and is quite expensive - riggers cost $80-$100/hour. Definitely not a project for anyone but rigging expert.

I am planning on installing two large pad eyes between the genoa track and centerline, attach a block to each one and use a pair of spare sheets for barber haulers. The same sheets can be used both to move the headsail clew inboard for tighter sheeting angle, as well as outboard for reaching to get a better control of headsail shape