Performance of Catanas

[2Hulls]

Hi Keegan - I've experimented both ways and am inclined to not use the main at all DDW. An exception may be when its pretty windy and I might want to raise the main some more when it comes time to sock the chute. (But I haven't yet experimented with unrolling the jib for this instead.) I've listened to arguments for using the main and its sheets as a backstay but I'm not convinced the rig is threatened without it.

What are your experiences?

Dave

[docgav]

Twice I have had a disaster running dead downwind under kite alone and under headsail alone. I was sailing away from shore and the wind suddenly increased and dropping the kite when screaming downwind under kite alone in 25 knots was a near disaster. We could not pull the sock over it. Releasing the clew caused terrible flogging and then the tack was released and we had this huge flapping sail off the masthead! We started engines, ran downwind flat out and eventually hooked a line and dragged it to the deck. Similarly we tried furling the headsail without any main protection in 35 knots and the load on the furler was too high and the feedline pulled a directing block off before we got the sail in.
I now run at least a triple reefed main in all conditions downwind. It keeps the boatspeed up if I need it and I can centralise the main and remove a reef while tracking along under the kite and then use the main to blanket the kite.
Gavin
(boats were 37ft Crowther supershockwave 'D Flawless' and 'Chaotic Harmony' Catana 42s)

[Keegan]

Originally Posted by 2Hulls

Hi Keegan - I've experimented both ways and am inclined to not use the main at all DDW. An exception may be when its pretty windy and I might want to raise the main some more when it comes time to sock the chute. (But I haven't yet experimented with unrolling the jib for this instead.) I've listened to arguments for using the main and its sheets as a backstay but I'm not convinced the rig is threatened without it.
Dave

I have had my symetrical only this season and have used it with the reefed main. I did add dyneema to the topping lift in March so that I could use it as a backstay and not have the main up at all.

Keegan

[Therapy]

Originally Posted by docgav

I now run at least a triple reefed main in all conditions downwind. It keeps the boatspeed up if I need it and I can centralise the main and remove a reef while tracking along under the kite and then use the main to blanket the kite.
Gavin
(boats were 37ft Crowther supershockwave 'D Flawless' and 'Chaotic Harmony' Catana 42s)

Now if I can just remember that when I get my cat.
That would be an "always" thing.
Thanks for the word of experience.

[David M]

I"m confused, why would you want to sail any catamaran dead down wind (unless you are constrained by a channel or land) when the polars for almost all cats indicate it is quicker to reach dead down wind by sailing on a broad reach...like around 130 to 150 degrees True?

[Factor]

Originally Posted by Therapy

Now if I can just remember that when I get my cat.
That would be an "always" thing.
Thanks for the word of experience.

Buy DocGavs book and write notes like that in it (Multihull Seamanship by Gavin LeSueur) then you wont forget, I carry a copy on board my boat and make notes all the time, I will have to cut it an put it into a comb binder with extra pages - its sort of growing into my ops manual.

[catty]

Originally Posted by David M

I"m confused, why would you want to sail any catamaran dead down wind (unless you are constrained by a channel or land) when the polars for almost all cats indicate it is quicker to reach dead down wind by sailing on a broad reach...like around 130 to 150 degrees True?

Yer you are right that's what the polars show but I'm not sure you will actually see that difference (small that it is by gybing downwind)when the course is square, in reality. Firstly by shying up the apparent wind angle is going to be all over the place as you surf and then slow in the troughs, so you are going to be working the sheets like a one armed wall paper hanger or hand steering (your choice). If you are cruising short handed on auto pilot just simplify things, strike the main, hoist the spinnaker or heady, set the course a little off square to avoid the accidental gybe, cleat the sheets and have a cup of tea. From experience very few loaded shorthanded cruising boats will benefit from sailing the angles. The slightly slower speed made good over the shorter distance sailed will be more comfortable as well.

[Joli]

Originally Posted by David M

I"m confused, why would you want to sail any catamaran dead down wind (unless you are constrained by a channel or land) when the polars for almost all cats indicate it is quicker to reach dead down wind by sailing on a broad reach...like around 130 to 150 degrees True?

It depends on where the mark is. In the 07 ARC the course was deep, so although the polars indicate you can sail quicker by heating things up your VMG is still limited by waterline. Look at the polar on post 65 and you will notice that the vmg for downwind sailing is ~9 in 20 knots of breeze. You can head up to 130 degrees and build boat speed but you still won't get down the course any quicker then 9 knots (the same is true for upwind sailing). The results of the ARC pretty much confirmed that waterline is speed. So the question that is asked are you better off with reaching ability or waterline? This months sail had an intersting comparison, a 46 Beneteau or a 36 FP Mahe. Same price, more living space in the Mahe, more waterline with the Bene. That's why they print wallpaper, take your pick.

Catty's dead on, when cruising (trade wind sailing) your gonna turn the nose down, hang some sail out there, and let the auto do the drivin. Much as I like high Hp boats I'm not sure they are faster for everyday cruising versus the a more moderate boat.

[Keegan]

Originally Posted by catty

If you are cruising short handed on auto pilot just simplify things, strike the main, hoist the spinnaker or heady, set the course a little off square to avoid the accidental gybe, cleat the sheets and have a cup of tea.

Yes, nothin' to it if you know how to do it! I need to make sure I have lots of tea for this type of thing.



Keegan

[fastcat435]

Originally Posted by 2Hulls

Hi Keegan - I've experimented both ways and am inclined to not use the main at all DDW. An exception may be when its pretty windy and I might want to raise the main some more when it comes time to sock the chute. (But I haven't yet experimented with unrolling the jib for this instead.) I've listened to arguments for using the main and its sheets as a backstay but I'm not convinced the rig is threatened without it.

What are your experiences?

Dave

I never use the main going down wind with the chute , all halyards are made from dyneema and I use the main topping lift ( also Dyneema ) to keep the mast in the right position. I have used the main in the past but in very light winds it interfered with the Gennaker and in harder winds it did not help to increase the speed so why bother?

Dave use your topping lift and tighten your main halyards when going down wind on the gennaker or spinnaker , it cannot harm and it is safer.

Gideon Goudsmit

[fastcat435]

Originally Posted by Keegan

Gideon: Nice looking boat! When do you think you will be building the first 55 Fastcat? How much do figure that will price out at?

Keegan

Hallo Keegan

we will start on the new 58 ft FastCat beginning of next year , the cost will be around the 1.3 mil euro mark fully equipped
the waterline leght is 55 ft 5 inches therefore the name 555

Greetings
Gideon

[Keegan]

Originally Posted by fastcat435

Hallo Keegan

we will start on the new 58 ft FastCat beginning of next year , the cost will be around the 1.3 mil euro mark fully equipped
the waterline leght is 55 ft 5 inches therefore the name 555

Greetings
Gideon

I would be interested in learning more about the 555. If I upgrade it will certainly be a cat that is 55-65 feet.

[fastcat435]

Originally Posted by Keegan

I would be interested in learning more about the 555. If I upgrade it will certainly be a cat that is 55-65 feet.

Hallo Keegan

If you send me your mail address I can keep you posted on all our models

Greetings and thanks for the interest

Gideon

[David M]

Originally Posted by Joli

It depends on where the mark is. In the 07 ARC the course was deep, so although the polars indicate you can sail quicker by heating things up your VMG is still limited by waterline. Look at the polar on post 65 and you will notice that the vmg for downwind sailing is ~9 in 20 knots of breeze. You can head up to 130 degrees and build boat speed but you still won't get down the course any quicker then 9 knots (the same is true for upwind sailing). The results of the ARC pretty much confirmed that waterline is speed. So the question that is asked are you better off with reaching ability or waterline? This months sail had an intersting comparison, a 46 Beneteau or a 36 FP Mahe. Same price, more living space in the Mahe, more waterline with the Bene. That's why they print wallpaper, take your pick.

Catty's dead on, when cruising (trade wind sailing) your gonna turn the nose down, hang some sail out there, and let the auto do the drivin. Much as I like high Hp boats I'm not sure they are faster for everyday cruising versus the a more moderate boat.

Still confused because VMG is what I am talking about as applied to catamarans and not monohulls. The maximum VMG for most catamaran polars sailing downwind is not 180 degrees but for something less, like 150 degrees for example.

What I am saying as an example is that if you have two identical cruising catamarans sailing towards a leeward mark at 180 dead downwind, the boat at 150 degrees will get there before the boat sailing at 180. Right? That's how it used to work racing Hobie 18's in my experience....you never sailed dead downwind if you wanted to win. I understand more waterline gives you more speed but I am comparing apples to apples with the difference being wind angle.

[David M]

Originally Posted by catty

Yer you are right that's what the polars show but I'm not sure you will actually see that difference (small that it is by gybing downwind)when the course is square, in reality. Firstly by shying up the apparent wind angle is going to be all over the place as you surf and then slow in the troughs, so you are going to be working the sheets like a one armed wall paper hanger or hand steering (your choice). If you are cruising short handed on auto pilot just simplify things, strike the main, hoist the spinnaker or heady, set the course a little off square to avoid the accidental gybe, cleat the sheets and have a cup of tea. From experience very few loaded shorthanded cruising boats will benefit from sailing the angles. The slightly slower speed made good over the shorter distance sailed will be more comfortable as well.

Ok...that makes sense. If you have the option of increasing sail area such as launching the spinnaker and sailing closer to 180 and staying more in the trough rather than crossing it then that makes a lot of sense. Thanks