Reef a spinnaker?

[team karst]

Looks like a 20 kt tailwind in 2 days. Does reefing make sense,; using a sock here. In a tristay cat, so downwind main/jib typically useless.

[Jagarwal]

How big is your headsail? Mine is a Genoa so I sometimes use only it, which allows a pretty deep angle, if wind is too much for the kite. Works for me but perhaps there is a better approach.

[alctel]

Yeah I wouldn't want to fly a spinny partially doused - that seems like a recipe for it jamming.

You mention being on a cat so I presume your headsail is pretty small else I'd say just use that - can you just use your main?

[caradow]

20 kts should not be too much wind for that boat.

Your AWS will be significantly lower.

However is that 20 kts constant with higher gusts?
May want to sail with kite and a reefed main, ? second-third reef or no main at all.
A monohull becomes a little squirrely with kite and no main because the main stabilizes the boat . Would not be a problem with a cat.

As long as you are comfortable in those winds, you could try it and if it becomes unruly just blow the sheet and drop it with the sock. No big deal. Just have someone ready on the sheet.
I guess the other factor not discussed is the cloth weight. if it is 1/2 oz. I would not do it. 3/4 -1.25 would not be concerned as long as it's good material.
Good Luck

[team karst]

Our side stays, being aft, prohibit large boom angles.

[thomm225]

No spinnaker is usually needed in 20 knots and above especially if you aren't racing.

Here I was using just a partial jib only as the furler jammed and the main halyard got fouled, but it was fine

Autopilot had the helm.

On my 300 lb. beach cats, I usually flew the spinnaker until around 22 knots then I'd bring it in before I pitchpoled.

https://www.youtube.com/watch?v=agtdrmAqojs

[thomm225]

In the upper 20's lower 30's, jib only would be perfect.

Here I mistakenly had my main up.....

https://www.youtube.com/watch?v=-nXfjcCuiPk

[fxykty]

We find our boat travels 0.5-0.6 of the TWS with a spinnaker downwind so that almost halves the apparent wind when running pretty square. We look at taking down the spinnaker when the TWS gets to 25 knots as any slow downs due to waves or whatever can mean rapid increase in AWS (our reefing plan says remove when over 15kts AWS).

Reefing a spinnaker with a sock isn’t possible as the sock and pull down line is not strong enough for that purpose. A way of reducing the power in a symmetrical spinnaker is to allow the foot to rise up (easing both guys/braces). This creates a larger belly up high and reduces the frontal area. If you have your mainsail up, easing the windward guy/brace and using the leeward sheet to pull the spinnaker around behind the mainsail will also work.

Regarding mainsail boom angle, 45* is just fine, as the top will twist further open anyway (if you ease the mainsheet and/or let the boom out beyond the traveller). A single or double reef won’t slow you down much if at all in decent breeze and will allow more air into the spinnaker.

For taking down the spinnaker with a sock we’ve always eased the leeward sheet until it luffs and collapses, then pulled the sock down. This always keeps the spinnaker nice and straight in the sock. After reading some of the posts in this thread we tried lowering it by easing the guy/brace to hide the spinnaker behind the main. What a schmozzle! The waves tossed the collapsed spinnaker around and back and forth such that it threatened to wrap around the forestay, got caught up in the rig, and went into the sock a twisted mess. Never again! (Though that is the preferred method to take down a spinnaker without a sock.)

[Tin Tin]

Spinnaker would only have 12-14 knots apparent, but if bigger gusts are expected then may be time to douse the kite before something busts. I think the trouble with pulling the sock down partially and leaving it there may induce twist in the sock lines and then it will not come down unless you let the halyard go and douse the kite half flying - not a fun job short handed in a strengthening breeze. We found that with 20knots of breeze the genoa sheeted with a spinnaker sheet would allow the sail to square off to the DDW breeze much better and everything is so much more controllable. You would still be doing 6+ knots surfing to 8 maybe. Potentially this could also be done with 3 reefs in the main, this allows wind to get around the top of the main to keep the genoa alive especially if wing on wing at an angle of 175 - 180. A prevention line from boom to side cleat could also be used and the whole system would be under less pressure with 3 reefed main.