Uncomfortable Yaw in Following Seas - Looking for Advice

[dfogal]

Hi Folks:

We have a Ranger Tug 29-S. We were crossing Lake Ontario today. The seas were forecast to be 1’ - but after a storm the lake took longer to settle down - especially at the shallow end of the lake. We had weird wave patterns. There was a 2-3’ wave front following us and maybe 1-1.5’ waves on the beam.

The net result as that as the following seas caught up to the boat (doing maybe 13 mph) the boat tried to torque sideways (yaw) and I had to work the throttle from being pushed sideways by the combination of the waves. The following seas would start the torque and then the beam seas would try to do the rest.

It as super uncomfortable.

Can you share your advice? I had the trim tabs down. I was doing about 2900 RPM and about 12-14 mph. I tried to manage the throttle but often felt I was running out of speed to push my way out of the ‘broach’.

How do you handle following seas? Any advice? I am super unhappy about how things handled today.

 

[dbsea]

I made a post about this in my C30 a while back. I experienced the same, but worse. 4-6ft following seas and 30kn of wind behind me. The boat would breach (yaw) coming down every single wave. This is because the boat is far too light and has too small a rudder to handle those kinds of conditions. Sounds like even in the seas you described, it struggled. I wondered If I was going to make it to the dock and was thinking about my abandon ship plan. You were doing all the right things - but the boat has its limitations.

 

[emtlibby]

Sometimes changing course by as few as 20 degrees can make a huge difference. Just zig zag your way home.

I'd suggest tabs not all the way down in a following sea, as you'll get steering by the bow when you get pushed. But truly, changing course a little can really change the feel. Also, your VMG towards your destination may actually improve.

Best,
Matt

 

[dfogal]

Thanks for the thoughts.

I think my best course of action is to ensure the lakes are really calm before heading out. We spend most of our time on rivers and canals - but each canal is an ‘island of calm’ connected to one of the Great Lakes.

I tried to adjust my course but the two sets of wavefronts in the confused seas meant that I could not find an angle that was safe from the broach/yaw. I tried slowing down and speeding up. The boat was slower than the wavefront - so I could not just throttle adjust to stay ‘surfing’ on a wave.

The wave period on the Great Lakes is very short - that means that the trough-to-trough distance is about 30’ - the length of the boat (https://swellbeat.com/wave-calculator/). So I think it’s a combination of the waves being faster than I was, the fact that we could fall into a trough, the following seas and the rudder/power limits.

The only answer I can come up with is avoid the problem. Unfortunately the wave forecasters for the Great Lakes (GLERL, Windy) are not that great. Maybe the right answer is to putter around the perimeter.

To be honest - I was shaking from adrenaline by the time I got into safe waters. I did not like the experience at all.

 

[SJI Sailor]

Agreed on avoidance in general and zig-zag to change the angle.

I would add: worst case, be prepared to wait it out and keep on eye on where you would go. For instance maybe turn around and go back. There is the old saying that the most dangerous thing on a boat (or a small airplane) is a schedule.

 

[S. Todd]

I found this post interesting because we have a 2021 R29S and boat the Great Lakes.
Back in the 80s I spent a fair amount of time "surfing" following waves on Lake Erie which is also very shallow. We had a Sea Ray with an IO and it was extremely exciting, always felt safe and much faster than going into a headwind and waves. The only time it felt unsettling was if the tabs were down and pushing the bow into the trough.
Last summer we were on Lake Michigan in our R29 doing a southbound run toward Little Travers Bay with a following sea that I would estimate was mostly 3 footers. We were running at about the same 2900 RPM that you indicated but making more like an average of 15 to 16 MPH. It was pleasant surfing and much faster than going into the waves. I do not recall if I had the tabs down, which is where they typically are when we are cruising, but because of the desire to keep the bow up, I suspect I had retracted them. Because the Volvo is supposed to be run hard every so often, I opened it up and set some new speed records for our boat in the 27+ MPH range. No broaching issues at that speed and it made short order of the trip. Granted, I did not have the issues you had with a secondary beam sea, so we may be comparing apples to oranges.
Stuck in a following sea my recommendation would be to retract the tabs (if the following sea is not directly behind just retracting one of them can be appropriate) and using some of the horsepower available to stay ahead of the wave behind you. You may not be able climb the next wave, especially if it is that every 7th wave that is 50% bigger (or even more) but you should be able to stay ahead of the following wave(s).
Prior comments about keeping a schedule are totally true. The next day the wind shifted and after beating into 4 footers for an hour we took refuge into an unplanned marina stop for the next three days waiting for the 6 to 8 footers to settle down. I love the Great Lakes, despite their short steep waves, and cherish their millpond days.

 

[Sandro]

I have a 2019 r29 CB and was in a very similar situation yesterday. Following seas/swells, 3-4 feet some definitely more - dead astern and then on a 20 degree angle. I'll second the comments on the tabs position above. I retracted the tabs and that made a huge difference. The bow has a very steep entry so you want to get that out of the water in any type of following seas. The stern then plants. The boat rocked and rolled and surfed etc as expected but was very stable with some, but very little yaw. 3000 rpm work well for grunt/torque and about the right avenge speed for about a 45 minutes in that seas state.

I have also learned that in and type of waves bigger than 1-2 feet, (head on, side or following) going slow (7 knots-ish) is very wet and uncomfortable. I get the boat on a plane, and then throttle back (as needed) - it will stay on a plane and be riding on the full 10 foot beam and very stable down to 12 knots if needed. stern is planted, bow is out of the water a bit and nice and stable and much dryer.

 

[dfogal]

Thanks. I also agree that the boat can be very wet when going slow. I have adjusted my approach a bit - trim tabs in to keep the bow up a bit - adjusting throttle to raise the bow as I go into a trough and bring it down as I go out on a wave crest. That seems to be helping. I LIKE going slow. I like the quiet of the engines. But in bad weather we just commit to burning the fuel. I hope that the yaw issue will be addressed with the trim tab change and tacking.

I have also decided to stick closer to shore and use the natural protection.

 

[mlanger]

Sometimes changing course by as few as 20 degrees can make a huge difference. Just zig zag your way home.…

I second this suggestion. I’ve zig-zagged my way though rough woter in my R-29 more times than I’d like to count. If you can’t avoid the conditions, you have to work your way through them The best way you can.

Coincidentally, I’m spending an extra 2 days at anchor off Georgian Bay to avoid nasty wave. Action on my beam out in the bay today. A friend in a much larger boat went out and came back; another friend in a sailboat told me I made the right decision. Avoiding bad conditions is always the best way.

 

[dfogal]

I second this suggestion. I’ve zig-zagged my way though rough woter in my R-29 more times than I’d like to count. If you can’t avoid the conditions, you have to work your way through them The best way you can.

Coincidentally, I’m spending an extra 2 days at anchor off Georgian Bay to avoid nasty wave. Action on my beam out in the bay today. A friend in a much larger boat went out and came back; another friend in a sailboat told me I made the right decision. Avoiding bad conditions is always the best way.

I’m hiding in Tobermory until Monday.