Originally Posted by SY Kelpie
Our new boat has three genoas and a twin groove luff foil.
When we set off next year on our bluewater
adventure, I'm thinking of setting up a twin headsail rig for the big downwind legs (Cape Verde to Carib).
We have only got one pole though, so I am wondering about using a block on the boom to sheet the other genoa. We have straight spreaders so we can get the boom well out.
Are there any downsides to this compared to having a second pole? I actually have an old boom off my previous boat which is a foot shorter than the pole on the new boat. But by the time you buy the necessary fittings to turn it into a pole, it's not exactly 'free' any more. Might be more hassle than it's worth?
I don't like sailing wing-on-wing. It's not stable and constantly risks gybing the mainsail
(or finding yourself on your side with a deadly-dangerous prevented main).
I've been flying twin jibs for years. It's my normal way of making the passage
from Half Moon Bay to Santa Cruz
or Monterey: 80 nm. I often average 7 to 8 knots for the entire voyage in moderate swell by surfing. My hull speed
is 5.8 knots.
I just take in my main and leave the tiller free without an autopilot
. There's no need to steer my full-keeled boat. Just sit back and watch. Twin jibs (on my boat) are self-correcting for headings off dead downwind. If I need to steer +/- 20 degrees of dead downwind, I accomplish that by adjusting the tensions on the jibs. Attached is a video that demonstrates the heading adjustments. Conditions: wind 5-8 knots with the boat anchored by the stern.
I've flown the jibs in up to 25 knots of wind. At that point, my boat will make 4 knots or more under bare poles downwind. So I just drop the jibs and enjoy the ride.
I have a spinnaker -- I never ever use it single-handed. If something is going to go wrong - it's the spinnaker. With "the twins," there's no broaching and no "roll of death."
I also have whisker poles that I only use in variable winds or rougher seas (rarely). The poles go up only if the jib
clews start snapping. I don't sail in the S.F. Bay where the winds are continually squirrelly. Those poles consist of hollow fiberglass
tubes (intended to be used as antenna
masts) that cost me $16 each. If they get "dipped" I expect them to break to save more expensive stuff. With the cut of my jibs, I'd have to be in really big seas or heel nearly 90 degrees to dip a jib
clew (YMMV with a beamier boat). Hasn't happened yet. I've heard of people using outrageously expensive whisker poles. Comeon: it's just a pole! And my fiberglass
poles weight only a little more than the $thousand carbon fiber versions.
One real charm of flying twin jibs is this: you can sail on an upwind reach, and the upwind jib will just lay over the downwind jib. Then, when you turn to a run: the two jibs will bloom open like a flower. Just use a separate jibsheet for each jib. You never have to leave the cockpit!
By the way, there is a gap at the luff between the two jibs where they hank on. That gap is beneficial - it acts like the apex vent in a parachute to prevent oscillation - which on a boat is known as "rolling." Oscillation makes parachute landings harder and that's why there's a hole at top of a round parachute canopy. On a boat - rolling consumes energy. I get very little of that. The "leakage" between the jibs is a good thing. Don't bother sealing it.
Here's where I got my poles: https://www.dxengineering.com/search/department/rigid-tubing/part-type/fiberglass-tubing?N=part-type%3Afiberglass-tubing&SortBy=Default&SortOrder=Ascending