Risk of capsizing a Lagoon 380 and reefing

[smj]

Originally Posted by CaptainRivet

yes they are genius, my favorite downwind sail. also good for autopilot, much less power needed as its 10-15m upfront the cat and no rounding up at the end of a wave possible.


simple, small, easy to rig and cheap if you screw it up.
just looked at some videos T8 dead downwind at 170 degrees with 18-20KN AWS 7,7-8,2kn SOG with giant 17x15 3-blade fixed props that were seriously braking on a 40ft Lavezzi with 2x50hp engines+liveaboard loaded 8.5-9t with all gear incl. around 350l water and 180l diesel.

So 7.5-8 kts. of boat speed dead downwind in 25-28 kts true wind?

[CaptainRivet]

Originally Posted by smj

So 7.5-8 kts. of boat speed dead downwind in 25-28 kts true wind?

Yes with giantic 3-blade 17x15 fixed props that were seriously braking. Got rid of them with even bigger Flex-o-fold 18x13 but didn't fly the T8 yet, from rest i would expect +2kn now.
But even 8 kn is fine for me here with the added security you cannot round up. With the 25-28kn came 3-4m cross swell and you start going down a wave and get slapped off course from another wave and the T8 just corrects that and pulls the cat back on course supporting the autopilot who needs much less power.

[JustMurph]

Originally Posted by smj

So 7.5-8 kts. of boat speed dead downwind in 25-28 kts true wind?

You'd probably be surfing at double the speed in your boat!

[Tupaia]

Probably not as efficient as "Kite Boat Systems" www.Kite-boat.com or Sky Sails www.skysails-yacht.com that both use parafoils but looks a whole lot simpler and cheaper.


My only concern would be the length of line from the mast head and the force that could be exerted high up if the deck level line was released or let go by accident. Does the mast head line attach to the bridle of the parachute or the rim and is this line loose when the para is flying?



I assume you could have an extra length of line equal to the height of the mast to keep things off the deck that attached to the existing spinnaker halyard. But that would still leave the parachute lines themselves to deal with.

[CaptainRivet]

Originally Posted by JustMurph

You'd probably be surfing at double the speed in your boat!

yes thats the average speed...surfing down the waves not really with 3-blade fix prop in 17x15...10kn then they were braking massivly...
thats what you get when a rich motorboater owning two motoryachts pershings 65 and 70 desicides to get additionally a "sailing" catamaran and switches out the 2x20hp for 2x50HP(even with technical offical drawings and certification from FP till 2x75HP) because you motor to slow.. i cannot surf a wave down with more then 10kn but i can motor with 15kn in a sailing cat

obviously the mast and sails where just decoration otherwise he would have figured that out himself...well he used the cat in 4 years for 19h



After buying and using it for over a year like it is to figure out what else i need to adapt and change for me. Well changing the fixed props to Flex-o-fold (not that easy as they are no reference, took 3 month to figure out the right FFOF props) last month fitting 18x13 FFOF cured that but i wasn't downwindsailing till now to see how fast i am now as i am in habour doing other mods too. weight penalty is actual not too bad at all bigger engine+saildrive is +80kg which i compensated by switching out the lead batteries (directly above engines) by Lithium and put them close to centre of the cat.

[CaptainRivet]

Originally Posted by Tupaia

Probably not as efficient as "Kite Boat Systems" www.Kite-boat.com or Sky Sails www.skysails-yacht.com that both use parafoils but looks a whole lot simpler and cheaper.


My only concern would be the length of line from the mast head and the force that could be exerted high up if the deck level line was released or let go by accident. Does the mast head line attach to the bridle of the parachute or the rim and is this line loose when the para is flying?

I assume you could have an extra length of line equal to the height of the mast to keep things off the deck that attached to the existing spinnaker halyard. But that would still leave the parachute lines themselves to deal with.

both lines are always tight, if the lower is really loose in above 10kn wind then your top line is too short (mostly) or your lower line to long. only in very light wind if the parachute is stalling a bit the lower line gets loose for a small amount of time. but in general lower line loose means you have no forward movement by the sail.
if you release the lower line the parchute colapses and no forces to the deck. thats what you also do (first pull top line in till mark on the top line) incase some of the little line break because you overloaded the sail.

but put a figure 8 at the end of the lower line so it cannot completly go out, because thats the absolute worst case because then you have a collapsed parachute flying at about mast height with the lower line flying up in the air.
then you whinch it to the mast with hailyard and put out genua to produce windshade so it stalls and comes down...happened to me once in the beginning but because the lower line is heavier that comes down first which after some attemps you are able to grab, put back onto bow roller and winch tight so it inflates again.

the worst that can happen is you operate it wrongly in strong winds and have a by far too short top line and a too long lower line that the sail creates a lot lifting forces to the lower line and deck where its connected. i done that on purpose with my old ketch to further reduce rolling but you could have lifted the whole 12t boat with this bow roller alone

both ropes (Hailyard and bottom line) i use have more braking strength then the each 10 little line together connecting to the cloth of the parachute which will rip before your lines do.

[smj]

Originally Posted by JustMurph

You'd probably be surfing at double the speed in your boat!

We were out last week in 15 gusting 20 going downwind. With only a single reefed main we were doing 9-11 and hitting 13. We decided to drop the main and go under 110% jib. With no sail up we were making a steady 5.5-6.5 under wing mast hitting low 7’s in the gusts. Under just jib it was 7.5-9, hitting mid 10’s in the gusts. I’m going to really miss this boat......

[CaptainRivet]

Originally Posted by smj

We were out last week in 15 gusting 20 going downwind. With only a single reefed main we were doing 9-11 and hitting 13. We decided to drop the main and go under 110% jib. With no sail up we were making a steady 5.5-6.5 under wing mast hitting low 7’s in the gusts. Under just jib it was 7.5-9, hitting mid 10’s in the gusts. I’m going to really miss this boat......

TRT1200 are great, sadly its the open and not CR version...CR i would have bought right away from you.

[smj]

Originally Posted by CaptainRivet

TRT1200 are great, sadly its the open and not CR version...CR i would have bought right away from you.

I would take the CR version but really like the open bridgedeck of the GT. Different strokes for different folks!

[JustMurph]

Originally Posted by smj

We were out last week in 15 gusting 20 going downwind. With only a single reefed main we were doing 9-11 and hitting 13. We decided to drop the main and go under 110% jib. With no sail up we were making a steady 5.5-6.5 under wing mast hitting low 7’s in the gusts. Under just jib it was 7.5-9, hitting mid 10’s in the gusts. I’m going to really miss this boat......

That's freakin awesome! You gotta love easily driven cats.
Are you replacing it with something else?

[smj]

Originally Posted by JustMurph

That's freakin awesome! You gotta love easily driven cats.
Are you replacing it with something else?

Yes, a Beach house......for now!

[aqfishing]

Originally Posted by Tupaia

Probably not as efficient as "Kite Boat Systems" www.Kite-boat.com or Sky Sails www.skysails-yacht.com that both use parafoils but looks a whole lot simpler and cheaper.


My only concern would be the length of line from the mast head and the force that could be exerted high up if the deck level line was released or let go by accident. Does the mast head line attach to the bridle of the parachute or the rim and is this line loose when the para is flying?



I assume you could have an extra length of line equal to the height of the mast to keep things off the deck that attached to the existing spinnaker halyard. But that would still leave the parachute lines themselves to deal with.

Sky Sails not marketed anymore. See attached

[Tupaia]

Originally Posted by aqfishing

Sky Sails not marketed anymore. See attached

Not surprised, complex to deploy and recover and expensive. Also a very limited market. Cheap cargo chutes is much more achievable.

[aqfishing]

Are there any discussion threads on round sails? Did a quick search but nothing jumped out at me. Have questions but do not want to hijack this post. Maybe a moderator can copy the relevant posts over to a new thread?

[CaptainRivet]

Originally Posted by aqfishing

Are there any discussion threads on round sails? Did a quick search but nothing jumped out at me. Have questions but do not want to hijack this post. Maybe a moderator can copy the relevant posts over to a new thread?

Send me a PM. There is not much documented, we did a comparison on a buddies lagoon 39 round sail,parasailor, genacker, code0 all about 80sqm except parasailor 105.