I just wanted to clear up what a winglet does. It simply makes the wing more efficient. It does this by forcing the air to flow over the end of the wing as it does in the middle of the wing, straight back. Without the winglets (and the same hold true for our sails) the air near the tip spills off toward the end instead of straight back. On our cats we lose at the top and the bottom.

I think a float that was airfoil shaped could work on square top sails. I don't think it would need to provide lift. Thats the last place you want to create drag.

There is nothing wrong with a Hobie Bob for anyone that feels it might help. I've recommended the Hobie Bob to many people.

I also believe that it is not neccessary for people with plenty of experience and are very familiar with righting a cat.

Mike Hill
www.stlouiscats.com

It would be easy to design a self-inflating mast float that's just a CO2 cartdridge and airbag that sit up top just for an emergency. (minimal windage and weight) It could be activated by a pressure switch that has a time delay, or by a tiny line that activates the mast top device.
Go for it!

Mike,

It looks like you have successfully understood my comment/question about a discuss or triangular shaped bobber that would be relatively flat. I see two problems, besides the obvious problem of building a thin and wide float that would withstand the impact force of a violent pitch pole roll.

1) Winglets are usually located near the leech, rather than the luff.

2) A agree with David L. in that they are not for everyone. I for one, will stick with a mast that can be intentionally buried for survival at sea in heavy wind.

To take of #1, I would consider a teardrop shape that would span the entire chord of the square top sail.

To take care of #2: If I decide to add buoyancy up there, I'll go with the smallest, cheapest West Marine inflatable vest. It is an easy project. That vest is contained in its own waist pack that can easily be riveted to the mast and a pull string lead down to the dolphin striker.

But honestly, I keep my mast sealed enough to endure a turtle experience. And if I have to stay turtled for an extended period of time, I won't count on being able to right the boat again. Why? Because I wont' count on my mast not having a very small leak that would eventually fill it up if left turtled for hours. After that, I don't think that an inflated horseshoe vest would be enough buoyancy to lift the mast and sails to the surface.

GARY

Jack,

That piece of work looks just as "amateur" as everything else that I've seen you build!

I'll bet you have the only, or at least the first "Prindle-Bob."

GARY

When surviving a storm at sea, wouldn't it be better to keep the boat upright, drop the sails, and use a drogue or sea anchor?

Not always. First of all, The only drouge I carry is a righting line and a gear bag. Second: Sometimes it is unsafe or impossible to upright a capsized cat. Third: A mainsail extending 31' beneath the surface is a pretty darn good drogue!

Fist of all, I am not a moron. A tornado touched down nearby and dragged my Hobie 16 along with its mooring into the channel, and then to the back of a cove and that is when it found the power lines. Don't make ASSumptions. I maybe I was wrong to say the Hobie bob looks amateur, but what do I know, right? I'm just saying that if I showed up to a regatta with a hobie bob on my I-20, I'd get laughed off the water.
Trey
I-20 314

Fair enough. My appologies.

SOME CLARIFICATION

First, most Rave skippers have never pitchpoled. They've only read about it from the few that have. Second, it's about a spectacular as a capsize but presents an unenviable position of not being able to recover with a single-handed skipper.

["Raves go over frontwards-- from flying out of the water at speed if altitude is poorly controlled, then coming down nose first. Result is a rapid, acute dive, as the inverted T-foils hit first and present a negative angle of attack while still going fast."]
A Rave will fly out of the water but usually only once or twice per owner when he is learning how to tension the flaps. When a Rave flies out of the water, it PANCAKES with a big splash because it does not gain enough altitude to arc into a dive. The pitchpole happens when, like a cat, the bows dig and that happens after an unexpected big gust or simply bad trim.

["The center hull fills immediately, stern is straight up."]
The central hull does not fill unless waves are breaking into the boat. In fact, when Dave towed my boat to shore I had been out there for five hours and more than a little hypothermic by the end of the day. There was no water in the hull because after a pitchpole the boat floats with the beam about a foot above the water's surface and the first opening to the hull is two feet above the beam.
Calm water would have to jump up three feet to get into the crew's seat hole. If the central hull had filled, Dave's boat would not have been able to tow me to shore.

I tried hanging off the stern while Dave's boat with a line tied to the stern tried to pull the Rave back to vertical. The problem is that pulling a pitchpoled Rave simply pulls the boat through the water. So, we gave up and I sat out there for five hours while the rest of the regatta was run. A drogue forward of the beam, opposite the pulling line attached to the stern, would have provided the resistance needed pull the boat back to vertical.

The Rave is seventeen feet wide with three T-foils five feet deep and a short rig. With a platform like that, there has not been one report of a Rave capsize.

Dean, would it be possible to flood one of the amas in an attempt to right it?

Gary
From what I've heard some "BOBS" break off upon hitting the water. Poor attachment? I think a small cross section like a foil would offer little resistiance entering the water. Like anything no matter how well you make it someone can and will break it.

For now when needed I'll run something boyant up...er down my mast.

Too Late!

auto inflator device for the mast:

Try this AntiCapsize Device

And this for the instruction details:
Instructions


Price listed on the website is $158 Eur including the VAT (16%)...so it's cheaper than the life jackets and the shape is better suited, volume is> higher. Mechanism is exactly the same (a salt pellet dissolves when submersed to release the trigger spring on the CO2 cylinder).

Further clarification...the air that flows off the tip of the wing (or sail) does so from the high pressure (windward) side to the low pressure (leeward) side, thereby reducing the pressure difference between the sides...and therefore the lift force...which is exactly the opposite of what you want to achieve...
This effect is known as "Tip Loss". It also occurs on our rudder/center/dagger boards.

Mike, I could have gone on and on and on like some do making the simple not. Point is the wing is more efficient with a winglet.

K.I.S.S.

Hi, Mike,

Sorry I'm late with these responses but I'm actually having to work for my money this week.

Flooding an ama might help in a capsize, a la Corsair righting, but I haven't heard of a Rave capsizing. The pitchpole is the booger that is to be avoided with a Rave and flooding an ama would pull the boat to that side and I think the resultant attitude would be a pitchpole with a terrible list. It might invite turtling. I dunno.

I have floatation in the bow, the mast, in the amas. One does the best to avoid it but, like I said, I haven't heard of that many pitchpoles since the boat came out in 1999. It's not a bad habit; just something to be aware of. No multihull is for normal people. If we were normal we'd all be fishing for bass in a boat from Wal-Mart.

Whoa! I have to have one of those anit-capsize things. Thanks for the 'site, Mike.

My CO2 life jackets were only $5 each at the surplus store but the cartridges are a bit pricey. If I had to use somehting like this it would be easier to hit a button than to run something up a halyard hoping that it didn't become hung up on something on the way up.

16% VAT. Ouch. I will have to start saving some pennies for a purchase in order to avoid the MasterCard guard at my house.

P.S.: I bought a slightly used mainsail from Steve Calvert last week. They do a good job down there. I can't wait until the snow melts here in Orlando.

I don't believe you pay VAT if the item is for export from Europe. Reason I stated the price to be lower than lifejackets...I bought a manual inflator type for crewing aboard Afterburner (52 ft beachcat!). It cost ~$180, though it does has a safety harness built in.

Mike.

I dug out a picture that I have of a MacGreggor 36 with just the sort of mast head float that I was suggesting. I also found where Tom House had posted a sketch drawing of it.
Picture and drawing

GARY

Mary and I had a Mac36 that had the wing float at the top and did very well with it.
We won most of the races we were in. Don't think it slowed us down any.

Great part was that the boat came with a self-righting system. After the boat was on its side (unable to turtle because of the masthead float), you pulled out the huge waterbag stored on deck, used the jib sheet and spin pole, attached the spin pole to a ring installed under the tramp on the hull and the other end to the jib sheet attached to the bag.
Fill the bag with water and winch the boat upright.

At least that was what the instructions said, although we never had to use it.

Rick