As a part of my job, I am sailing with different boats, both mono and multis. To me , it's senseless to say "you have to reef at this wind speed, or this". Every boat behaves differently. For monos, most of the cruising boats have 130-135% genoa
, rather short and light keels and tend to heel excessively as the apparent wind reaches around 20 kts. Not only the ride becomes uncomfortable, because of the heel angle, half of the rudder
came out of water
and you start loosing the control of the boat. I start by furling
and ease a bit the main traveller. Next step is to reef the main; this goes on until you can fully control the boat. Typically fo a cruising mono, up to 30-32 kts, half furled genoa + 1 reef on the main is OK.
For a catamaran
, again for a heavy charter
boats with conservative sail area, you can usually go up to 22-25 kts apparent easily. The cats have a genoa much smaller than the main, so I start with a main. If a second reef is needed on the main, then, I start furling
the genoa as well. This is around 30 kts.
All this, is of course subject to change according to sea state, the crew on board, visibility, etc..
I assume everyone with some experience, knows more or less how their boats behaves in rough conditions. So, if you feel comfortable with yr Oyster
up to 25 kts, you don't reef.. For less experienced people or someone on the boat that he/she doesn't know well, I'd put the reef even at 15-17 kts.