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rgano 10-18-2019 09:49 PM

Extend the rudder of a Pilot 30 for following seas
This question was asked on the Yahoo Mainships Group, but that site is falling into disuse, and I am choosing to post my comments on this question here, having made notice of the fact there.

I think that the 30 Pilot II I have must be carefully handled in a following sea, and if the sea is significantly high, you have no business out in it, especially running down sea. The first thing to do IMHO is to raise the trim tabs to raise the bow up and come to a speed which matches the wave speed if possible. If the waves do overtake the boat, the raised bow will help to limit bow steer as the steer rises up. This is not to say a rudder with more authority given to it by an extension might no lessen the helm turns needed, but it might also result in an oversteer and a broach.

Slowing to hull speed and trailing about a hundred feet of mooring line or rode from either quarter cleat be the best option when the seas begin to overpower the available authority of the steering system.

Beekeepergreg 10-23-2019 12:23 PM

Interesting and makes sense, I guess like a sea anchor as of sorts.
When you say rode, chain and rope?
For our 30 MS Pilots what size and makeup should I try?

djmarchand 10-23-2019 03:00 PM

Sailors let our a bight of a hundred or two of heavy line which forms a sea anchor to keep the boat from outrunning waves. Not sure if it works in a DE style boat.

Actually the Pilot 34 handles better than its sister the flybridge 34T in a following sea, probably due to a couple of feet less beam. I was able to tame down my 34T with a gyro based autopilot. I could keep on a straight path after a few minutes of hand steering, but the non gyro autopilot steered 30 deg wide S turns. The gyro dampened it to 5-10 degrees, not great by tolerable.

Heading off by twenty degrees also usually tamed a following sea, so you tack downwind.

Yes, part of the problem is the relatively small rudder area, but increasing the rudder size would slow the boat down quite a bit at 15 kts.


rgano 10-23-2019 08:31 PM

In direct answer to Greg's question, we are discussing fiber rode/line. Size is probably not as important as length here because the drag is along the length of the line, and braided is probably less effective than twisted line. I would think 5/8 inch twisted nylon could be carried aboard a 30 Pilot in sufficient length to make a difference, but that length would have to be experimented with. As David mentions, you could deploy a single length in a bight between the stern cleat, but a pair of lines would also be possible. I would suggest you run in calm water at 8-10 knots sometime and toss over even just a 30-foot length of 5/8 to get a feel for the force. I will bet you cannot pull it back aboard.

Beekeepergreg 10-24-2019 12:43 PM

If stuck in a following sea and have to trail a "Sea Anchor", rig up a fish school simulation ( chains ) and follow it with a high speed lure--maybe grab diner on the long ride home.
Now we wouldn't be surviving a pain in the ass following sea but fishing.
My luck with fishing....well another time.

Shrew 10-24-2019 01:26 PM

Why not look at a drogue? A lot of sailors are fans of a Jordan series drogue, but I suspect it will require you slow down to 6 knots.

Marlinmike 10-28-2019 09:59 AM

Had experience delivering a few small ruddered boats (Trojan 32, Bertram 28 etc), larger rudders help greatly, even running on one engine where the 28 Bertram would go in circles with stock size!

psneeld 10-28-2019 04:51 PM

You guys need to figure out the difference of a sea anchor and a drogue.

Dragging a long line (warp) can be the first step.

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