Cruising cat - sub 90 degrees tack upwind

[Dave_S]

I was showing how little of the boat is submerged to counter 7.25t and so how little extra would be needed if it were overloaded.

But it's always good to hear some compliments.

Thanks 😊

[44'cruisingcat]

Originally Posted by Dave_S

Not sure about the math. I'm fairly skinny (haha, not myself... I mean my boat :-) ) around 15:1 hull ratio and 1m wide at its widest, about 0.4m wide at the stern, and 0.0 at the bow. We are 7.25t for a couple of nights away (2.25t above bare weight and 0.25t over suggested target weight) and draw 0.42m. So 7.25t draws 42cm and don't forget the first cm might only create 5kg of displacement increasing with depth to the last cm which maybe 230kg of buoyancy. From its current waterline it will only increase buoyancy further with depth.

I can't think what I'd put on to add up to 5.25t payload but I would expect to move the waterline no more than about 12cm from where it is now with an additional 3t. What do people take to add up to 5t or more ?

I would guesstimate my weight if I were to do a crossing at 7.5 to 7.75t or about 2cm from where I am now.

Nice! But why isn't the antifoul up to the windows?

[Uncle Bob]

Originally Posted by 44'cruisingcat

Nice! But why isn't the antifoul up to the windows?

Love it.
You can be a bad man when you want to cant you.

[GRIT]

We had a beat down the Chesapeake earlier this month. We had to sail pretty close to the wind to do it. I didn't fuss with the computer to see if I was at maximum VMG, but I thought the tacking angles were as good as we did in our old monohull.

https://youtu.be/7JIwFnT_xMA

Cheers.
Paul.

[fxykty]

Here’s a track from last week beating up a channel on the last of head current going slack. 12 knots TWS and we had first reef and full set tacking jib up. Average speed 6.1 knots anchor up to anchor down over just under 7 hours and 45 miles. So yes, 90 degree tacks are possible but likely not the fastest for VMG. However our new sails and recently fully scrubbed bottom (that was a workout with scotch brite pads) do seem to like a tighter AWA angle than our previous bagged out Hydranet sails - about 5* AWA closer and slightly better speed.

Sorry, I don’t do YT so don’t bother with videos. If you guys really want, I can do that on our next upwind sail.



Photo taken a couple weeks earlier going upwind near Great Keppel Island, with a full main.

[Tupaia]

New main sail looks nice, what is it?

[tamicatana]

1992 Catana 40S, laden for liveaboard/cruising, Hydranet sails from 2013. current either abeam or ahead (current running S to N). ESE wind speed around 15 g20, 7-8kt boatspeeds

[fxykty]

Originally Posted by Tupaia

New main sail looks nice, what is it?

Both main and jib were designed and built by Zoom Sails. Material is string reinforced (Dyneema and Technora) membrane (Italian made) with heavy polyester taffetas on both sides. We decided on white for least thermal heating and also to remove the high-tech look. We considered a square top but I really don’t trust the loose head, especially when reefing in higher winds and off the wind, so the round top is good enough. We still need to tighten the lower forward diamond to remove some of the prebend from the bottom half of the mast - that’s the cause of the wrinkles from the lower luff.

The main is about 8% larger than the original sail plan and has much deeper reefs, especially the third, based on our sailing experience in the previous 4 years. One big improvement was placing the bottom three battens such that they are each just above each reef. The previous main had both first and second reefs above their nearest battens and that was a real pain. We spend almost half our time on first or second reef - one of the joys of an easily driven sailboat.

The jib is also nearly 5% larger than original - mostly due to longer luff since we no longer have a luff foil furler and secondly due to a fuller leech. The new sail’s design is a huge improvement over the previous jib and it trims much easier. That is party due to it not having to operate partly furled and it is designed for a maximum working AWS of 30 knots. We swap to the staysail at 22-25 knots AWS when offshore, and 26-28 knots AWS near shore (mostly dependent on sea state).

[GRIT]

Those sails look great!

Do you have Radar, and if so, is it mounted on the mast, or aft on a pole? I'd like a "mast sweeping" self tacker too, but I don't want to have to loosen the sheet to get it around the radar. I'm considering moving the radar to accommodate a self tacking jib.

Cheers.
Paul.

[Tupaia]

Originally Posted by GRIT

Those sails look great!

Do you have Radar, and if so, is it mounted on the mast, or aft on a pole? I'd like a "mast sweeping" self tacker too, but I don't want to have to loosen the sheet to get it around the radar. I'm considering moving the radar to accommodate a self tacking jib.

Cheers.
Paul.

What about mounting it to the side on a spreader?

[GRIT]

Thanks Tupaia:

I considered mounting it on the spreader when we first built the mast, but I'm convinced an 18" radar, mounted on the side of a 13" mast will have a large blind spot, especially close up. I know folks do it, but that only leaves 2.5 inches on each end.

I had previously considered mounting it on a post aft, but a B&G rep suggested the radar's efficiency might be compromised by "wet sails"! Having used it for a year now, I'm pretty sure it won't be much of a compromise, as I'm sure it would have been reported by now; I see quite a few mounted on poles aft.

Thanks for your response.

Paul.

[Tupaia]

Originally Posted by fxykty

One big improvement was placing the bottom three battens such that they are each just above each reef. The previous main had both first and second reefs above their nearest battens and that was a real pain.

Sail makers particularly "mono" sail makers seem to get this wrong all the time. With a slightly kicked up boom and raked mast, if the batten is below and close to the reef point it acts like an out-haul and the sail jams. I rejected a mainsail because of this. Sail maker didn't listen and went with the way he "always" did it. Been there done that got the tee shirt.


Be interesting to see how the string sail lasts we haven't had good experience. Problem seems to be moisture wicking along the strands from the cut edges.

[fxykty]

Originally Posted by GRIT

Those sails look great!

Do you have Radar, and if so, is it mounted on the mast, or aft on a pole? I'd like a "mast sweeping" self tacker too, but I don't want to have to loosen the sheet to get it around the radar. I'm considering moving the radar to accommodate a self tacking jib.

Cheers.
Paul.

Our radar is mounted in front of the mast. But due to our forward diamond stays and their respective forward spreader already cause a lot of noise on the front of the mast. The leech is slightly hollow to allow for that, though there is considerable overlap.



Since our jib traveller track is straight we do ease the jib sheet during a tack - it’s the only adjustment we have to do during a tack if we’re not using running backstays. During a tack the jib traveller comes to the middle of the track and sticks there. This has the benefit of providing a backwind during the tack. Once we’re 15-20* AWA to the new tack we ease the sheet about 1 metre. This makes the jib more powerful for the exit from the tack and we bring the sheet in gradually as we regain speed.

[GRIT]

Thanks FxyKty. That's doable then.

I'll have them hollow out the leech a bit to help get around the radar.

Wouldn't a curved track be just as bad for easing the sheet? I have the option, since I don't have a track for the self tacker yet. But I figured a straight track would require less easing of the sheet, since the ends would be further from the tack than the centre would be.

I also have fittings on the mast for an inner forestay, which will be removable, for heavier winds.

That photo helps a lot. Thanks.

Cheers.
Paul.

[fxykty]

Originally Posted by GRIT

Thanks FxyKty. That's doable then.



I'll have them hollow out the leech a bit to help get around the radar.



Wouldn't a curved track be just as bad for easing the sheet? I have the option, since I don't have a track for the self tacker yet. But I figured a straight track would require less easing of the sheet, since the ends would be further from the tack than the centre would be.



I also have fittings on the mast for an inner forestay, which will be removable, for heavier winds.



That photo helps a lot. Thanks.



Cheers.

Paul.

The problem with a straight track is that the centre is closer to the tack than the ends, so an upwind sheet setting that has considerable foot tension will result in the traveller moving to the centre and then not wanting to extend out again.

A curved track, if matched in radius, will have equal distance from the tack on every point on the track.

Another factor is to rotate the track forward so that it matches (is perpendicular to) the sheet angle. Our track is flat on the deck and the traveller car is rotated on the track by sheet tension, which also causes it to jam.

Are there higher strength balls for Harken travellers? We’re using the standard brown Torlon balls and they get crushed fairly quickly in our jib traveller.