Athena 38: Sailing with Genny only

[Hasbeen]

In the old days, in the far distant past, when men were men, & women liked it that way, mainsails were hanked on to the mast.



Particularly when going to windward in a moderate seaway the luff of the main so attached was very useful in supporting center of the mast, reducing the center pumping each time the boat hit a wave. This had a very useful effect up to about 65 degrees apparent. Winding on back stay tension, & bending the mast to flatten the main was also helpful.


I did make one very rough passage, 1100 miles from Honiara in the Solomons to Cairns Australia under jib only, & worried the whole way. The wind was about 65 apparent, & way above normal trades. There was a huge swell running, 35 to 40 Ft high, but so long that the yacht did not even feel it, but it made a very confused local cross swell of 6 to 10 feet.



The wind was rarely under 35 knots, & with any main up the boat would not come under about 8.5 knots, & was leaping off the back of the larger cross seas. I set a 165 Sq Ft jib, sheeted inside the shrouds, as flat as I could get it, stalled right out. This got the boat down to 5.5 to 7.5 knots, but the mast was still pumping.


I pulled a couple of spare sheets up the mast on the spinnaker pole topping lift, lead via the back of the head sail track, & winched on pretty hard. This helped, but I was still worried for the mast for the 6 days of the crossing.


Head sail only is fine down wind, but I don't like it on the wind.

[Mr B]

After hundreds of miles in a straight line, Using the GPS for speed,
I tried the Main and Genoa full up in all positions,
I actually got an extra 1 knot in speed, With both sails up,

Im a cruiser, one knot makes no difference to me, 24 Nmiles in a 24 hour period, Maximum, Big deal, Im not in a hurry to get any where,

Except that I have to go out on deck to put the main up or down,
Face into the wind to get it up and down easily,
Which can be quite hairy and dangerous in big waves, Single handed,
The Genoa works fully from the cockpit, Safely and I dont get wet either,

So I stopped using the main, Strapped it down and put the cover on it,
Using the Genoa only, I got between 5 and 10 knots average, constantly, Depending on the wind,
High winds, I only used a small bit of the Genoa to maintain my speed and to keep me under 10 Knots,
I need 3 knots of wind to move, and then my boat usually travels at 3 or 4 knots under the prevailing wind strength, But I dont exceed 10 knots in boat speed, Ever,
I dont want to break any thing as Im single handed,

I took my Genoa to a sailmaker here as the stitching had come undone as it was perished from old age, 19 years old,
$100-00 and it was fully restitched, She said the Genoa was in very good condition,
I told her about the Genoa only sailing on my Gemini Cat, and the GPS speed trials I had done,
She said to me, You dont need a mainsail on a Catamaran as they sail very well on a Genoa only,
She also stated that the Black thread lasts longer than the White thread due to UV perishing the threads, I have the Black threads on mine,
I have a twin spreader, Fractional mast with 8 wires holding it vertical,
6 of these wires are 1/3 and 2/3rds up the mast, so it stays straight vertically,
I have a topping lift, Holds the boom up off the Bimini roof,
I have a wire backstay to the rear of the transom from the top of the mast, , with an adjustable rope pulley system to tighten the back stay if needed, Its reccommended to keep the back stay loose, By the Manufacterer,

The back stay splits into two above the Bimini, so one wire goes to each side of the transom, One wire to each hull, Approx 10 feet between the two fixing points,
I have that tightened to just take the slack out of it, To stop the top of the mast from moving forwards when the Genoa is fully extended,
Its a self furling Genoa, 150 size,
I also have another wire that runs from about half way up the mast to a point in the deck, 2/3rds forwards, between the mast base and the Genoa, Jib, Screacher, Spinnaker anchor point on the deck, , Its next to the boats central Anchor cleat, The Genoa's base fixing point,

This is for a Gemini 105MC, 1200 of them have been built and I havent heard of a mast breaking or coming down yet,

This does exclude being smashed to pieces on the hard and in a Marina during cyclones and Hurricanes,

Cheers, Brian,

[LagoonJim]

I have a Lagoon 500. Manual says same, no head sail without main. All points regarding spinnakers/ginnakers valid. I run mine no main all the time. Agree with logic on mainsheet and topping lift in principal. I’m just very judicious about it, light light wind.

My thought has always been it’s because mainsheet could accidentally be spilled, and topping lift with shackle, snatch blocks, cam locks, etc, are not exactly as strong as proper backstay cable and solid rigging fittings.