Roger implies the limits of ***function**** of headsail furlers.

A headsail on a 'furler' can only be reduced by 30% SA and still
retain any good shape. Beyond 30% reduction and you wind up with a
'BAG" shape instead of a usable sail shape for any 'upwind' work.
135 X .70 = 95% So, you can reduce a 135 down to a 'working
jib' (100%) size without shape problems. A 150 can usually only be
reduced to a 105, etc.

A furler usually cannot tolerate heavy luff loads, as would be
necessary to change the luff entry shape (the 'forward curve shape' at
the luff) of a jib/genoa; crank on luff tension to a furler with a
halyard and to *Jam*. ..... probably the prime reason that you'll
never ever see a genoa/jib furler on a serious racing boat.

My impression is that most 'kroozers' dont know (or care) how to
'shape' sails ... as one hardly ever sees a 'kroozer' without a
furler.

So Roger, put your working jib back on board when travelling as your
can roll that puppy down to a 70% sail.

Same arguments apply to mainsail furlers - sail shape.