Hydraulic self steering

[dana-tenacity]

I remember reading about a self steering device that towed an impeller which gave hydraulic pressure to drive some sort of hydraulic logic brain and steer the boat. Excess power was trickled into the batteries. Now I can't find anything about it on the web. Anyone know what I'm talking about?

[Kai Nui]

No, but when you find out, I am interested. Of course, keeping it from becoming bait might be an issue.

[Craig Harlamoff]

I read several cruising articles where the sailboat was towing a brass propeller that spun a generator. The propeller was drug a ways behind the boat. A rope transferred the spin the stern mounted generator. They were able to charge their batteries for much of the trip. I remember reading that somewhere off Australia, the couple had the propellor bitten off by a large shark. From this, they learned to paint the propellor black, to reduce attention from the toothy kinds.

[Talbot]

http://www.lvm-ltd.com/aquagen.htm

Aquagens are water towed generators suitable for all sailboats and sailing speeds in blue and coastal waters. They can provide sufficient power to satisfy all power requirements whilst under sail. The towed turbine travels 1-3 metres below the surface and can therefore be used in shallow coastal waters as well as on ocean crossings. Two models are available:

• The Aqua4gen which starts to generate power at 2.5 knots boat speed
• The Aqua6gen which starts to generate power at 3.5 knots boat speed

The Aqua4gen produces up to a continuous 11 amps at 8 knots boat speed when fitted with large turbine blades (115mm) and 10 amps at 10 knots boat speed when fitted with smaller turbine blades (90mm).

The Aqua6gen produces up to a continuous 16 amps at 12 knots boat speed with 90mm turbine blades.

[SkiprJohn]

Aloha Dana,
I too remember an article about that self steering system. I read the pros and cons and mentally tossed the information because of the complexity of that system. I lost a Walker Log along with the propeller to either a longline fisher or a toothy critter in the middle of one night and don't want to tow anything that might rip off my taffrail again. I'll check my old records and see if I can find something on the system and let you know. There are several windvane systems that are much more efficient.
Kind Regars, --JohnL--

[Kai Nui]

The generators have been around for awhile, but loosing them to sea critters is a common problem. A couple of years ago a company came out with a watermaker that ran on the same principal, but it seems to have lost popularity in the last year (or just never caught on). Probably for the same reason.

[dana-tenacity]

Thanks everyone. I was interested coz a windvane (my first choice) isn't appropriate on a fast multihull and I have a serious dislike of anything electronic.

[Talbot]

There is a water-driven generator that doesnt suffer from that problem, and also provides serious power for about 1/3 kt loss of speed. There is only one problem - its seriously expensive.http://www.duogen.co.uk/ here is a link to a video (broadband needed) showing deployment and recovery:

http://www.duogen.co.uk/images/xraislwr.avi



The watermaker referred to is the waterlog. The idea is good, I am yet to be convinced of the effectiveness.

[Steve Rust]

I remember reading about the hydraulic unit in Multihulls Magazine quite some time ago. It seemed to get good reviews but I don't know why it never caught on. I think it may have come from Germany and gone by the name of Windpilot. I believe there is a windvane that now goes by that name but they are not the same.