Windvane Steering? Autopilot or Both for Offshore Cruising

[colemj]

Originally Posted by Paul L

Mark,
Given your brushes with lightening, what's your offshore plan for loosing your primary AP from a lightening strike while multi-days from a port?

We have a catamaran that is unable to mount a windvane, so our decision is made for us.

Currently, our offshore passages are no longer than 3-4 days, so we don't feel the risk of losing the autopilot, although steering for even a day or two would suck for us. We won't be doing longer offshore passages for a while yet, as we are not in a hurry in life and after exploring the rest of the Western Carib, we will probably explore the Pacific side of Central America and Mexico for a couple of years before going further into the Pacific.

So our offshore AP plan right now is to ignore making offshore AP plans.

Thinking further along, I have made some changes to the boat after the lightning strike to mitigate damage from another possible strike. These include changing the type of VHF coax going up the mast and installing lightning arrestors on that portion of the run (the main entry into the boat's electrical system from the previous strike), installing a N2K wind sensor that allows it to be easily disconnected during electrical activity (the secondary entry point from the strike), and putting surge protectors on the AP computer circuit.

We also chose MFD helm instrumentation that can all be used as AP control units and can be disconnected and stowed in less than 30 seconds during lightning activity. We will do so with one of these if lightning activity is around. We can also control the AP through our computer, although we are limited to the "steer to waypoint" nav function using that.

We have a spare hydraulic AP ram - these are pretty lightning proof, even when connected, because they are just a simple motor without any electronics or delicate wiring and isolated from the main electrical system by the AP computer. At some point in the future, we will get a second AP computer and store it appropriately. With a second AP computer, we will have a complete second AP on board.

Then, we will buy a gun. If we lose both AP's, I will shoot myself.

Question for those who have crossed the Pacific - how frequent is lightning during the long passages on this run and how difficult is it to avoid storm cells when they do occur? I imagine the ITCZ has some activity, but nothing much outside of it. Most of the lightning we have encountered has been coastal, and everyone we have met that have been hit have been hit around coastal areas. I haven't read any accounts of people being hit on passage in the Pacific, although I admit my research is pretty short in this area.

Mark

[SimonV]

Oh and my wind pilot is a Sailomat.

[Zanshin]

While a lot has been said regarding the pros and cons of windvanes in the previous pages, I didn't see anything regarding my biggest problem that is preventing me from getting a vane in addition to my autopilot.

Vanes need to be installed at, or very close to, the centreline of the boat. Any boat with a sugar-scoop stern or which otherwise uses the stern for entry or dinghy storage will have issues when using a vane. That big swim platform or boat entry is going to be severely restricted. In addition, a windvane big enough to also function as an emergency steering system is going to make backing into a docking difficult indeed, even if it is of the swing-up type.

[SimonV]

Originally Posted by Zanshin

While a lot has been said regarding the pros and cons of windvanes in the previous pages, I didn't see anything regarding my biggest problem that is preventing me from getting a vane in addition to my autopilot.

Vanes need to be installed at, or very close to, the centreline of the boat. Any boat with a sugar-scoop stern or which otherwise uses the stern for entry or dinghy storage will have issues when using a vane. That big swim platform or boat entry is going to be severely restricted. In addition, a windvane big enough to also function as an emergency steering system is going to make backing into a docking difficult indeed, even if it is of the swing-up type.

The sailomat can be off set, can be used as an emergency rudder, and swings up out of the way.

[Zanshin]

The sailomat can be offset, but only by about a foot or so, not 1-2 meters so that the swim platform can be used. With that amount of offset when the boat is heeled to the other side the rudder part of the vane would need to be (on my boat) over 1 meter deeper and changing that would change the loads on the whole system. I'm not at my home PC now, but I have a couple of mails with them on the subject, as I really wanted a windvane on my previous (sugar-scoop stern) Jeanneau.

[Sailmonkey]

Cape Horn will build an offset vane, there are several pictures on their website of such.

[Zanshin]

Cool Beans - I'd never heard of Cape Horn Windvanes and just browsed their site. The offset they mention is just enough to clear a boarding ladder or the like, no examples of an outboard eccentric installation are shown. But I've sent them an e-mail sind I still really want a windvane on my boat and I'll see what they respond.

Here's an example of a Beneteau 393 from their site showing how one would lose an aft swim platform with a centreline mount:

[S/V Alchemy]

Originally Posted by Sailmonkey

Cape Horn will build an offset vane, there are several pictures on their website of such.

I was going to note that...most of the Cape Horns I've seen (which haven't been a lot, admittedly) seem to be on sugar scoop sterns via a large (like 4 or 5 inch) SS "pipe".

They seem to work as I don't see them getting replaced.

[robert sailor]

Getting hit by lightning sure would ruin your day. I have crossed the Pacific several times and the only time I even saw lightning was between Fiji and the Marshall Islands. Having said that I was raised on the prairies where lightning is a normal occurance but I have never seen lightning activity like I did on that passage. We had it steady for the better part of 24 hours and it was like strobe lights at a 1970'ds disco dance. I really wondered why we never got hit, luck for sure. We had one of those bottle brush ion dispersers on the mast head, not sure if they work but maybe better than nothing. I threw the portable GPS in the stove but didn't worry too much as I had my sextant as backup.
We were sailing on the outside of the Baja and had a steel boat off our beam and it got hit by a lightning strike and it lit the whole boat up. We could see the complete boat including the underbody like it was on display, damndest sight! If your sailing to the South Pacific on the milk run its pretty rare to see lightning.

[robert sailor]

Sugar scoops are easier to get in and out of dingy's when a vane is mounted as it gives you something to hang on to, assuming it doesn't impede access which usually means it needs to be offset. Hydrovanes are offset on many boats.

[msponer]

Originally Posted by colemj

Question for those who have crossed the Pacific - how frequent is lightning during the long passages on this run and how difficult is it to avoid storm cells when they do occur? I imagine the ITCZ has some activity, but nothing much outside of it.

I did not see any intense lightening in the Pacific between Galapagos and Australia. I think this is the common experience. I do not know weather well, but I feel that the squalls are too small to make the nearly continuous and intense kind of lightening you see in other parts of the world.

I think with a fast boat you could avoid many squalls in that area. On our previous boat, a 40' monohull, we weren't fast enough to weave through them effectively, and so we tended to just stay on course and see if they'd hit us.

[Jim Cate]

FWIW,

I agree that lightning is fairly uncommon whilst doing the milk run, say from MExico to NZ via French Poly, etc. What lightning we have seen on that route was not associated with small storm cells, but with the passage of troughs and cold fronts. One can somewhat avoid the small cells but not the larger systems, so there is always a chance of being exposed to lightning activity.

On the other hand, lots of lightning whilst cruising Fiji and Vanuatu and the Solomons. And perhaps the worst area (not form personal experience) is a bit further on... SE Asia and the PNG/Indonesia area. A shocking number of our friends have been struck in Indonesian waters...

Oh, and Australia has lots of lightning as well...different seasons in different areas, 'cause it is a big place, but yachts are often victims!

Cheers,

Jim

[Orrjames]

Check out the Monitor windvane promo video(s) parts 1 and 2 ( On You Tube). They have a dude on there who has been through the thick of it all and has a compelling case for the windvane.

[Andrew Troup]

Regarding windvanes on walk-through sterns, you can mount them on a swinging frame, like a spare tyre on an SUV.

- - - - -

Anyone reading this thread in search of enlightenment should bear in mind that there are ideologies at play here.

If, from familiarity with someone's opinions on other relatively unrelated matters, you can reliably predict what they will write on this one, then I think that's something to factor into your assessment.

As an unrelated example of the syndrome I'm alluding to: If someone's views on, say, guns, or climate change, can be reliably predicted from their views on (say) religion, then I think it's suggestive that their intellectual processes are being held hostage in some way.

On the other hand, it's great to knock ideas around with people who are persuaded, sometimes in ways which surprise themselves, by the unique merits of individual cases.

Everyone has a guiding ideology or set of them, some more than others, and if that's a sin I'm guiltier than most.

What I'm edgy about is those who offer prescriptive advice to others, based on their own ideologies, without knowing enough about the other's situation and guiding principles.

I don't have a problem with "This is what I do, for these reasons" but I'm not so enthused about "This is what you should do, because that's what I do"


"This is what you should do, because that's what everyone does" -- appealing to the supposed wisdom of the masses -- is a modification of this, which put in an appearance further up this thread.

I'm underimpressed by where that leads, especially in a world where marketers have become sophisticated hostage-takers of consumers' minds. Ratings-led TV is an extreme example.

However it's also a problem in non-commercial contexts: think Germany after WW1

[Jim Cate]

FWIW,

One might well have a look at the German WindPilot vanes. They have a mount which adapts well to sugar scoop sterns, and can be dismounted fairly easily. Not sure about off-center installations, but the proprietor is good about answering questions via e-mail.

Cheers,

Jim