Jib blocks

[chuck]

Am fairly new at sailing. Have 23' oday and there are jibs blocks 1(1 per side) with a series of holes to move block ahead or back. I can never see any difference in where I put them. Probably am not particular enough. Anyway under what conditions should the blocks be moved? What do you look for? thanks for any help.

 

[Joe Barrett]

Flat vs Full shape

Jib lead blocks control shape and draft of the jib. Moving blocks forward gives fuller shape and more power thru chop and waves and best for light air. Move leads aft when the wind picks up to flatten the jib, weather helm reduced substanially. Medium air will be somewhere in between.With properly adjusted Genoa blocks the upper and lower telltales will break at the same time. Jib blocks also control the leach of the jib, move them forward on a reach to close the leach, move them aft when sailing close hauled to open leach of the jib.