Sailing Downwind with Autopilot

[saintpeter]

It seems that the TopHat and other breeds with a keel-hung rudder have a bad reputation for steering in seas, with the wind on the quarter.
This is the only direction that the tillerpilot just will not handle.
Picture short, steep 1-2 metre slop in Port Phillip or Bass Strait - even hand steering involves anticipation and a lot of helm.
I have tried reefing the main or even handing it altogether, with little improvement.

So....has anyone tried streaming a small drogue (off the windward quarter) to keep the stern from tripping over the bow????

On the other hand.......Today, the tilllerpilot cable connector finally became unusable. With the wind forward of the beam (the further forward the better) Kittiwake steered herself perfectly with a 'lashed' helm - better than with the pilot. Lashing is achieved by using a light stainless chain across cockpit and onto pilot pin on tiller (link-by-link adjustment). This was best with the #2 headsail full and the first reef in the main (14-18 kts), set to de-power just before the h/sail. Sorry, no photos, but this is so simple.

After 60 years of sailing I am still learning, and despite occasional vices, the TopHat is a remarkable little yacht.

[lockie]

First off mea culpa, I have a Compass 28 not a TH, but its shape in the water is very similar so hopefully my comments will be of some help.

When I sail directly downwind or with a quartering sea in PPB chop or in Bass Strait, I find that either of my tiller-pilots can do a better job than me, which is a great relief because it's bloody hard work. I have a Raymarine ST2000+ and a Simrad TP22.

You might want to try "tuning" yours to see if it helps: both the ST and TP can be adjusted to optimise response in demanding conditions. The user manuals describe this fairly well. With following/quartering seas you need a rapid tiller response (low damping/seastate) and fairly high rudder gain.

If you have a Simrad you can make these adjustment "on the fly" while the TP is steering in Auto mode. That makes it quite easy as you instantly see the effect while the TP continues to steer.

By contrast, the ST2000 is a pain in that it must be taken out of auto mode to access the calibration settings. Of course this means (if you are solo) you have to steer with your knees while trying to read the manual and push the right button, with the boat corkscrewing like mad. It might be worth just a quick heave-to make the adjustment easier, but it's still a pain compared to the TP.

I also drop the main in these conditions if the wind is up much. This helps with steering as it moves the centre of effort forward (and avoids the risk of gybes and/or the hassle of rigging a preventer).

Keep fiddling, you'll get there.

Cheers, Graeme

[saintpeter]

Thanks Graeme.
My pilot is a Raymarine ST2000. I have never understood the sensitivity/gain adjustments, so I will read up on them.
However I must first wait for new parts for the power cable (socket and plug), which are on their way. The connection has been unreliable for a while, and last sail it just gave up.
I almost always sail solo, and one really needs reliable steering for any trimming or tacking manouevres.