Boat wallows in rough water
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Comodave
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We crossed Lake Ontario in about 6’ off the starboard quarter in our last boat. The rain was so hard at times the radar would white out. It took about 6 hours and it was uncomfortable. My wife was pretty upset when we started but I assured her that while it was uncomfortable it was not dangerous. I could do a better job of steering than the autopilot but no way was I going to be able to do it for 6 hours so I just left the autopilot on and we rocked and rolled. The autopilot kept us within about 20 degrees either way on our course line. Overall it wasn’t fun but the alternative was to sit for 5+ days because the weather was going to be really bad for the next week. Obviously it worked out.
Hippocampus
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Until you get into very expensive autopilots that have artificial intelligence and can learn and predict APs are limited. Once had a ride in a boat with the high end NKE system which was truly an eye opener on how poorly most APs steer. But you’re talking tens of thousands of dollars from what I understand.
There was a study done comparing average speed and velocity made good between a skilled human, a servopendulum wind vane and a AP. I believe that study was over a decade ago so used a “dumb” AP. Still the AP did the best, vane second and human dead last by a significant margin. However now with AI APs would think the margin would be even greater. Still I don’t think APs are worried about comfort but rather boat performance.
There was a study done comparing average speed and velocity made good between a skilled human, a servopendulum wind vane and a AP. I believe that study was over a decade ago so used a “dumb” AP. Still the AP did the best, vane second and human dead last by a significant margin. However now with AI APs would think the margin would be even greater. Still I don’t think APs are worried about comfort but rather boat performance.
Comodave
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Yes, and the autopilot can go for hours on end and not complain about sore shoulders…
Slowmo
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It sounds almost as you're dealing with two issues, one is the roll and the other is 'wallowing' and what sounds like the need for excessive steering correction. Lots of good comments on the way you quarter and how you manage the waves. As to how much effort is required to keep her on course that is primarily a rudder size question coupled with speed. The easiest thing to try is to add a bit of speed in those conditions, I find that helps a lot in our current boat. Typically I always quarter the waves, when we had a round bilged full displacement cruiser this was essential. The hard chines and slow roll of our Tollycraft makes it much less sensitive but still you have to keep an eye on each wave, that's the reason I never use the AP in these conditions. I want to be able to adjust to the wave before it hits me, not after.
OP
OP
Island Time
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I have enjoyed all the comments. We had decided to enlarge the rudder already, our boat just does not back up well at all, so we are thinking rudder size as it does seem very small for the boat. Will know how it worked this summer and do a post for sure.
North Baltic sea
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Hi,
Adequate rudder, AP (gyro) with acceleration sensor and an efficient hydraulic pump does its job better than the skipper, with the Raymar system itself, which has been replaced with a better pump. Acceleration sensor The 9-axis sensor monitors the boat's movement in all three dimensions and guarantees a dynamic accuracy of about two degrees in all conditions.
I almost always drive with AP, but sometimes I practice driving without it, because everything can break down.
NBs
Adequate rudder, AP (gyro) with acceleration sensor and an efficient hydraulic pump does its job better than the skipper, with the Raymar system itself, which has been replaced with a better pump. Acceleration sensor The 9-axis sensor monitors the boat's movement in all three dimensions and guarantees a dynamic accuracy of about two degrees in all conditions.
I almost always drive with AP, but sometimes I practice driving without it, because everything can break down.
NBs
Hippocampus
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Dry stack, engine intakes look like they’re on top of the house, steel with a keel. Our boats would downflood. Airseps wouldn’t keep up. Engine(s) would stop. We would also not clear the green water as quickly so would actually wallow in the strict meaning of the word. Most recreational boats are wet exhaust with air intakes to the engine room a few feet up from the designed waterline on the sides of the boat. Nordies usually have them higher on the aft bulk head of the salon into the aft cockpit positioned on the long axis. Those two boats were taking boarding seas from every direction. Our boats wouldn’t survive imho.
Agree with NB. Our new simrad AP does a better job than me. On both sail and power have always gone to standby periodically and watched the rudder angle indicator noting if the boat has lee or weather helm. Do that with the AP on first. Often the ride improves with neutral helm but it may require “tacking “ to get where you want to go. That works with wind waves (chop) not so much with swells. My boat (and many rec trawlers) bow blows off. AP has to work much harder to correct. Always in the same direction.
Agree with NB. Our new simrad AP does a better job than me. On both sail and power have always gone to standby periodically and watched the rudder angle indicator noting if the boat has lee or weather helm. Do that with the AP on first. Often the ride improves with neutral helm but it may require “tacking “ to get where you want to go. That works with wind waves (chop) not so much with swells. My boat (and many rec trawlers) bow blows off. AP has to work much harder to correct. Always in the same direction.
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OldDan1943
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Remember, the AP response speed can be adjusted.
OldDan1943
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Once these guys ‘commit’ I dont see a way they could choose to turn back.
I would need a clean pair of skivvies upon docking.
I would need a clean pair of skivvies upon docking.
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rslifkin
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Most of our boats are also faster than the boats shown in the video. So we'd have a better shot of staying ahead of the breaking waves and not getting slammed to the extent they are. I absolutely agree that if most of the boats on this site (mine included) started to take boarding seas to that extent, things would go bad pretty quickly. I certainly wouldn't try a bar crossing that looked like that.
You're right on that Hippo!
No matter how good the captain... Most pleasure boats would likely go down in those conditions.
I just inserted that opposing current, high wind, wave bounce back, deep hollow, cresting white cap atop confused swells grueling water condition as extreme example of what a boat and crew/captain can withstand. I've been in some rough conditions when younger... don't ever plan to be so again. The guy at times walking around aboard with camera was NUTS! Couple of explicative uttered by those filming that fiasco from shore. Captains on those trawlers were working their assssses off to not meet Davy Jones!
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Taking water through the engine room vents doesn’t mean the engine will be ingesting water unless the vent is plumbed directly to the engine. Sure, it’s not a good thing to get seawater coming in the vents, but it isn’t a death sentence.
I’d be more concerned about having a big salon window blown out.
I’d be more concerned about having a big salon window blown out.
OldDan1943
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If you are taking on water through the vents, you will notice the boat slowing down, the boat is slow to respond to the rudder, bilge pumps running and not shutting off.
You're very correct - Blown window
C lectric
Guru
I assume that wallow means you are running in a following sea? Correct?
What speed are you trying for?
Does the boat slew around , ie. try to turn broadside to the waves coming from behind or on the stern quarter?
I have a 32 ft boat. I slow down to about 5K in any conditions over about 3 or 4 ft. when from behind or on the stern quarter so my travel is definitly less than the waves.
i have travelled in much larger waves, including the big easy going swells but BIG chop. Didn't like it but with a few mods to my handling it became tolerable.
If you are travelling to close to the wave speed or a wee bit faster the boat may tend to perch on the wave peak and then when it comes off and accelerates forward you don't have enough control so the boat slews around and can turn broadside.
WHen the wave speed and the boat speed are to close together the rudder has no real water flow past itself so then very little effect on the boats direction which contributes to the slewing and can make it VERY difficult to correct.
If you are travelling slightly faster than the waves the boat will slide down the wave front and when the bow digs into the wave ahead you have lost most control, the rudder is not very effective and the whole boat may slew around broadside or close and of course tilt.
I learned to slow down so the waves catch me and pass underneath. I am far less likely to have my bow dig into the wave ahead.
On my boat I can adjust the rate of rudder response and turn it to the fastest response, least number of wheel turns for more immediate rudder action.
A few times that still was not enough, maybe I misjudged or the waves were nastier than I realized and the rudder was not enough. THe boat had started to slew around. I then gave the engine a sharp, short burst of power which got me control again, stopped the slewing and straightened the boat up.
So I see from your comments that you have become more comfortable with your vessel which is good.
I almost didn't bother replying but I thought someone else may be looking for advice, thus the result.
Hope it helps someone.
What speed are you trying for?
Does the boat slew around , ie. try to turn broadside to the waves coming from behind or on the stern quarter?
I have a 32 ft boat. I slow down to about 5K in any conditions over about 3 or 4 ft. when from behind or on the stern quarter so my travel is definitly less than the waves.
i have travelled in much larger waves, including the big easy going swells but BIG chop. Didn't like it but with a few mods to my handling it became tolerable.
If you are travelling to close to the wave speed or a wee bit faster the boat may tend to perch on the wave peak and then when it comes off and accelerates forward you don't have enough control so the boat slews around and can turn broadside.
WHen the wave speed and the boat speed are to close together the rudder has no real water flow past itself so then very little effect on the boats direction which contributes to the slewing and can make it VERY difficult to correct.
If you are travelling slightly faster than the waves the boat will slide down the wave front and when the bow digs into the wave ahead you have lost most control, the rudder is not very effective and the whole boat may slew around broadside or close and of course tilt.
I learned to slow down so the waves catch me and pass underneath. I am far less likely to have my bow dig into the wave ahead.
On my boat I can adjust the rate of rudder response and turn it to the fastest response, least number of wheel turns for more immediate rudder action.
A few times that still was not enough, maybe I misjudged or the waves were nastier than I realized and the rudder was not enough. THe boat had started to slew around. I then gave the engine a sharp, short burst of power which got me control again, stopped the slewing and straightened the boat up.
So I see from your comments that you have become more comfortable with your vessel which is good.
I almost didn't bother replying but I thought someone else may be looking for advice, thus the result.
Hope it helps someone.
Hippocampus
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Need to to look at how engine controls are run and where batteries are placed. Also all other components. Have had two experiences showing me the importance of this.
One occasion had the engine intake through hull shear at the flange. Before controlling this water came over the battery boxes as it splashed around. All electrical equipment failed to function. Could see this happen even with a crash pump running as intake for pump is in the bilge and air entry is on the side of the ER for most coastal recreational trawlers. Water also came over the vents for fuel and water tanks from combination of seastate and water splashing around. Filter for air intake got soaking wet although well above the highest point the water ever got to.
Second occasion was doing a Bermuda race. Two wave trains. One just abaft the beam. The second on port quarter. Every fourth to fifth time they would be in synchrony and monster large and breaking. The boat would literally disappear with only the mast just below the gooseneck still showing. The boat would rise and you’d do it again. Boat was a Bob Perry designed from the ground up as a BWB. Very few recreational trawlers are so would be rapidly overwhelmed.
Have no argument our boats are more capable than us. But only wished to point out the sea is stronger than our boats. To say otherwise is hubris.
One occasion had the engine intake through hull shear at the flange. Before controlling this water came over the battery boxes as it splashed around. All electrical equipment failed to function. Could see this happen even with a crash pump running as intake for pump is in the bilge and air entry is on the side of the ER for most coastal recreational trawlers. Water also came over the vents for fuel and water tanks from combination of seastate and water splashing around. Filter for air intake got soaking wet although well above the highest point the water ever got to.
Second occasion was doing a Bermuda race. Two wave trains. One just abaft the beam. The second on port quarter. Every fourth to fifth time they would be in synchrony and monster large and breaking. The boat would literally disappear with only the mast just below the gooseneck still showing. The boat would rise and you’d do it again. Boat was a Bob Perry designed from the ground up as a BWB. Very few recreational trawlers are so would be rapidly overwhelmed.
Have no argument our boats are more capable than us. But only wished to point out the sea is stronger than our boats. To say otherwise is hubris.
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