Correct tiller pilot size for small boat with big rudder

[KelseyB]

I'm looking into tiller pilots, specifically Simrad ones because I have a B&G system. The boat is 30 feet and displaces about 10,000 pounds, so technically the TP10 (up to 32 feet), TP22 (up to 34 feet), and TP32 (up to 37 feet) should all work. However, I've also got a pretty big rudder relative to the size of the boat, and I've found that it generally gets a decent amount of resistance and I need to be pretty heavy-handed with it, relative to what you'd expect for a 30-foot boat, especially under power because the propeller is quite close to it. Do I need to err on the higher side of power in my tiller pilot because of this? Has anyone found the lower range of these tiller pilots to not be as powerful as they claim?

[Bill O]

Originally Posted by KelseyB

I'm looking into tiller pilots, specifically Simrad ones because I have a B&G system. The boat is 30 feet and displaces about 10,000 pounds, so technically the TP10 (up to 32 feet), TP22 (up to 34 feet), and TP32 (up to 37 feet) should all work. However, I've also got a pretty big rudder relative to the size of the boat, and I've found that it generally gets a decent amount of resistance and I need to be pretty heavy-handed with it, relative to what you'd expect for a 30-foot boat, especially under power because the propeller is quite close to it. Do I need to err on the higher side of power in my tiller pilot because of this? Has anyone found the lower range of these tiller pilots to not be as powerful as they claim?

It seems you answered your own question w/the balance of your boat and the amount of power needed to steer the boat. Would go oversized and the TP32 would be my choice if there wasn't too much difference in price. Usually w/the oversized motor there isn't too much power difference when using it in "normal" conditions.
Didn't look at the sail dimensions on your boat, but if your helm is getting heavy under sail when the wind pipes up, you may want to reef the main sooner to reduce the rudder load. Boat will sail as fast (or faster) w/less rudder deflection/drag.

[Mike OReilly]

My view is you should always err on the side of heftier when it comes to all autopilots. If it fits, and you can afford it, go to the biggest.

[fourlyons]

I own and have used both the tp10 and tp32 for the last 13 years and a few thousand miles. They both handle my boat fine, 40' and 10 tons. However my boat is very well balanced with a very light helm. The tp32 has a faster response, the ram moves back and forth faster. Also the tp32 has a recirculating ball screw drive, which has much less friction and should last longer than the screw thread drive of the tp10 and tp22. I would recommend the tp32 in your case.

[coopec43]

I think ypu'd be best advised by the manufacturer of the unit.

I believe there are quite a few factors that need to be taken into account.