Genoa blocks

[Warren]

I have a 23 O'Day with CDI Roller Reefing and a 130 genoa. When I decide that the full sail is too much for the wind conditions and I roll up some sail, what rules govern where to place the genoa lead blocks. I was out yesterday and needed to reef the genoa, and had no clue as to where to place the blocks for optimal sail performance. I undertand that there are no absolutes, however I am just looking for a guide to get me started.

[Justin - O'day Owners' Web]

Warren - Leaving the blocks in place actually works pretty well. Assume for a moment that you will leave the sail fully deployed. Moving the blocks forward will increase the draft of the sail and power it up. Moving the blocks aft will flatten the sail and depower it. So - as you reef the sail and the tack moves forward and the blocks stay in place the relationship between the blocks and the sail is the same as it would be if the sail stayed the same and the blocks moved aft - flat and somewhat depowered. Exactly what you need heavy air.Justin - O'day Owners' Web

[Del Wiese]

Consider adding some tell tales so that they are near the luff of the sail when furled. You can then determine the position of the car by the usual method of making all tell tales "break" at the same time.