Catamaran tacking angles , really that bad???

[mark_morwood]

One other consideration that I forgot to mention for our particular situation as a cruising boat, is by the time we were reefed for those conditions our sails were definitely sub-optimal for pointing. Either 2 or 3 reefs in the main and a 40% furled jib didn't give great sail shape for pointing so we were never anywhere near the theoretical optimal pointing angles in those conditions.

With respect to the question on TWS v AWS, I always kept our wind instrument speed on TWS so that 28 knots is what the instruments believed the TWS to be. There are all sorts of reasons why that might be off by a bit, but having been there and experienced quite a lot of different conditions offshore I'd say they were reading about right.

[arsenelupiga]

Originally Posted by fxykty

Slowing down is a more effective tactic to stop launching off waves than is bearing away, if you still want to go somewhere upwind. To bear away far enough so that the increased speed of the wider angle doesn’t make launching off waves more of a problem you would be on a beam reach.

Assuming that you are properly reefed for the conditions, fastest VMG is provided by slowing down and heading higher - as the smaller wind angle increases VMG faster than the slower boat speed decreases it. Keep track of your leeway and keep just enough boat speed to prevent leeway dramatically increasing. In bigger seas that will be a wider angle than in flatter seas.

Use both daggerboards (if you have them). Be mindful of the sea state and whether tripping is a risk.

Try dropping your boom to 10-20 degrees below the centreline, just far enough that it just starts getting backwinded by the headsail. Keep the sheet tight and drop the main on the traveller. Flatten the mainsail through more outhaul and more halyard, if possible. This will produce less side force and decrease leeway.

Run one engine and motor sail - very helpful to keep the boat speed from slowing down too much at the tighter angle.

I’m not sure that steering around waves is a thing for catamarans, at least for upwind where you’re approaching waves at an angle. You would turn up to set up your windward bow to spear through an approaching wave, then you would bear away along the top of the wave to avoid launching off it. By that time your leeward bow encounters that same wave at a wide angle that will launch it of that wave.

The reality is that for cats you generally have to sail wider angles to have more speed to overcome higher leeway (compared to monohulls), due to the increased aerodynamic drag at higher wind speed and increased wetted surface drag at slower wind speeds. Bear away far enough and the increased boat speed and reduction in sideways force due to wider wind angle will practically remove leeway. But for upwind, you need the tighter angle.

thanks for pointers, will test it out. regarding steering around waves, this is not that intensive 'racer steering', this in my case applies when say we get 'launching' wave every 1 min or less often. I simply use remote AP to increase or decrease TWA for 10 degrees, so flipping AWA for 15 degrees or so. AWA would look something like 40 when smooth road ahead or 55 when avoiding crash. I am yet to prove this strategy improves VMG. Sure saves the structure and improves life on board.

[arsenelupiga]

i cant believe it, found that magic stick to go better upwind. This time we were sailing north against current and yet ~90 deg tacks between 5.5 and 6.5 kn. Some older designed sporty looking larger cat was left behind and was sailing larger angle also. Amazing.

[Factor]

Originally Posted by arsenelupiga

i cant believe it, found that magic stick to go better upwind. This time we were sailing north against current and yet ~90 deg tacks between 5.5 and 6.5 kn. Some older designed sporty looking larger cat was left behind and was sailing larger angle also. Amazing.

The tides roun the whitsundays can move pretty well, what was the tide doing here?

[Uncle Bob]

Originally Posted by arsenelupiga

i cant believe it, found that magic stick to go better upwind. This time we were sailing north against current and yet ~90 deg tacks between 5.5 and 6.5 kn. Some older designed sporty looking larger cat was left behind and was sailing larger angle also. Amazing.

Certainly seems that your cat is something special. Previously you have described how it performs substiantly better than even lagoon advertises, exceeding their published polars,"how could have lagoon got it so wrong", routinely performs better that other performance cats etc etc.
You can never sell the thing, you will never find anything else as good.

[arsenelupiga]

Originally Posted by Uncle Bob

Certainly seems that your cat is something special. Previously you have described how it performs substiantly better than even lagoon advertises, exceeding their published polars,"how could have lagoon got it so wrong", routinely performs better that other performance cats etc etc.
You can never sell the thing, you will never find anything else as good.

i am close to getting similar results as late monte. See his 6K review of L 400. Nothing special about our boat, except I learned to sail better. Yeah, you are right, we do sometimes perform surprisingly well. And other times not that well. Seem to be corresponding to hull cleanliness.

[arsenelupiga]

Originally Posted by Factor

The tides roun the whitsundays can move pretty well, what was the tide doing here?

we had current against us, going south, in this particular case, not much though.

yeah, i am really happy with upwind performance. CF panel told me 5 or so years ago L 400 can do 50 apparent, that is the best. Now we seem to be sailing 30 to 35 app routinely.

[searoom]

That is amazing performance!
We sailed on a friends just built James Wharram Tiki 30 catamaran. The boat of plywood, epoxy and glass had little to no extra gear on board as we only sailed in a Maine Harbor area. She pointed pretty well with plenty of speed given her lightness. I know multi’s go well if they are kept light.

[django37]

Originally Posted by arsenelupiga

i cant believe it, found that magic stick to go better upwind. This time we were sailing north against current and yet ~90 deg tacks between 5.5 and 6.5 kn. Some older designed sporty looking larger cat was left behind and was sailing larger angle also. Amazing.

Congrats! Yes - it is possible - I'm often asked to help owners to get their condomarams to get better VMG to windward, and if the sails are not too bad (but many are), we can get TWA 45 dgr. More difficult is the to get 90 dgr between tracks because of leeway. Most owners are very afraid to pull enough in halliards and sheets - especially mainsheet. Mainsheet controls the sag in the forestay, as we dont have standing or running backstays. Clean bottoms, folding props, good sails and most important: lots of practice - but most owners do not care, and this is how the condomarams got the reputations: they cant go to windward.

[arsenelupiga]

Originally Posted by django37

Congrats! Yes - it is possible - I'm often asked to help owners to get their condomarams to get better VMG to windward, and if the sails are not too bad (but many are), we can get TWA 45 dgr. More difficult is the to get 90 dgr between tracks because of leeway. Most owners are very afraid to pull enough in halliards and sheets - especially mainsheet. Mainsheet controls the sag in the forestay, as we dont have standing or running backstays. Clean bottoms, folding props, good sails and most important: lots of practice - but most owners do not care, and this is how the condomarams got the reputations: they cant go to windward.

thanks for support. i was also ignorant of upwind sailing, partially due to negativity on CF regarding lagoon upwind abilities. Every book says it as well. I can understand the sentiment, spending 2 mths in whitsundays, where virtually every charter cat is motoring and these lagoons with apartment like spaces and livability must initiate envy/disgust of camping style sailors.

We have relatively young sail, around 7 k nm, replaced 3 years ago.

Now we are preparing for world cruising, and upwind abilities have become important as any other point of sail. Your numbers are great, my ambitions modest - to be hopefully able to use 3kn direct upwind for passage planning purposes.

my wife really enjoys upwind sail so i do not hesitate any more to make upwind passage.

Thanks for the hint will play with it.



happy sailing.

[django37]

arsenelupiga: Sailed from Denmark in June 2015, across the Atlantic with the ARC+ the same year. Across the Pacific in 2016 to Brisbane/Boat Works. 2017 up the east coast to Darwin, then up to Singapore to be shipped to Turkey here in the Med. Have spent 3 years cruising in Greece - very lovely. But in all less than 3% was upwind sailing. Mainsail is a laminate of Dacron/Carbon/Dacron, Genoa is Hydranet. The 380 is my 7th cruising cat, and the first I have not designed myself ..

[Happ]

Originally Posted by django37

Congrats! Yes - it is possible - I'm often asked to help owners to get their condomarams to get better VMG to windward, and if the sails are not too bad (but many are), we can get TWA 45 dgr. More difficult is the to get 90 dgr between tracks because of leeway. Most owners are very afraid to pull enough in halliards and sheets - especially mainsheet. Mainsheet controls the sag in the forestay, as we dont have standing or running backstays. Clean bottoms, folding props, good sails and most important: lots of practice - but most owners do not care, and this is how the condomarams got the reputations: they cant go to windward.

Having owned several trimarans you do have to crank in the main sheet quite hard to get the mast raked back with the side stays. Sometimes as much as 6 or 7 deg. On one of the trimarans we set the mast rake back as far as we could get it until the boat slowed down. Next time you’re at the harbor look at the rakes of the cats. Always way back.

The Polars are usually very good if they come from the architect. If they are made by individuals then sea state, wind, sail condition and bottom condition all come into play. Top race boats that have been prepared properly (keels templates, great sail, clean bottoms) often have the polars on speed instrument right next to the boat speed instrument. You sail the boat to the polars. If boat speed is faster then polars you head up if speed is slower you fall off. I am talking sometimes its only a degree or less.

[Seaslug Caravan]

Originally Posted by arsenelupiga

i was also ignorant of upwind sailing, partially due to negativity on CF regarding lagoon upwind abilities..

Not sure you should pay any attention to the armchair brigade. Once someone starts the CV with "I have owned XX boats " its time to reallize they dont know what to buy.

Here are some real world racing results for the Lagoon "Troppo".

There is a picture of the particular boat in this link.

https://www.abc.net.au/news/2020-10-...oices/12745320

The races were conducted over 12 NM course with both windward and leeward work in 8 to 14 knots and strong tidal influence. The 3 benchmark vessels are Mrs Palmer ( tennant GBE), Cockatoo ( Crowther Harrier 29) and Kuching ( Easton 43) all sailed by competent sailors from " A cats" etc, and all fitted with daggerboards. Toby on Tropppo ( the Lagoon) is also a good sailor.

As you can see from the results there is not a huge difference. In fact very little in race 1.

See race 1 and 3 at the bottom of the attached link 2018-19 wet season series.

https://www.dbcya.com.au/racing-resu...-8338a6b9-8160
As usual most pundits donts seem to know their ears from there elbows.

[arsenelupiga]

Originally Posted by Seaslug Caravan

Not sure you should pay any attention to the armchair brigade. Once someone starts the CV with "I have owned XX boats " its time to reallize they dont know what to buy.

Here are some real world racing results for the Lagoon "Troppo".

There is a picture of the particular boat in this link.

https://www.abc.net.au/news/2020-10-...oices/12745320

The races were conducted over 12 NM course with both windward and leeward work in 8 to 14 knots and strong tidal influence. The 3 benchmark vessels are Mrs Palmer ( tennant GBE), Cockatoo ( Crowther Harrier 29) and Kuching ( Easton 43) all sailed by competent sailors from " A cats" etc, and all fitted with daggerboards. Toby on Tropppo ( the Lagoon) is also a good sailor.

As you can see from the results there is not a huge difference. In fact very little in race 1.

See race 1 and 3 at the bottom of the attached link 2018-19 wet season series.

https://www.dbcya.com.au/racing-resu...-8338a6b9-8160
As usual most pundits donts seem to know their ears from there elbows.

i do not know about other cats but L 400 can use gennaker for upwind work up to 10-11 kn. One has to tighten spi halyard really well and not every boat can take that structurally - not stiff enough according to sailmaker. From my calcs L 400 should be able to do 4 kn VMG in 10 kn true - boat speed around 6 kn at 30 app sail inside shrouds. My current laminate gennaker was not designed properly for upwind so i can only do 3.2 kn VMG in 10 kn. With this addition, Lagoon could do better in that race, i guess, especially if unloaded. For cruising, probably feature not worth having as new well designed smaller laminate gennaker would be required. Maybe one day...

[Jim Cate]

^^^^

Upwind with a gennaker? That's kinda unusual...

Jim