Stabilizers: A Must for Passage-Making?

[Hippocampus]

The problem with ultralights is they must be kept ultralight to perform. Same for performance multihulls . Over weighted safety can deteriorate as well. This is the opposite of what you want as a cruiser. Every time we’ve sold a boat been amazed how much stuff (watch Carlins routine) needs to be removed. For racing captains get ridiculous. Raced a Chris White designed tri to Bermuda. Owner was even interested in eliminating weight from our sea bags.
Had occasion to watch production power cats, sailing cats and mono hulls going to weather traveling from Tortola to north south BVI. All were charter boats. The multis hobby horsed terribly. A privately owned Outremer was with them and stayed flat as we did. The power cats did the worst not having the benefit of the stabilization from sails. Think as regards ride there’s much to say for tris if going with power. Especially those with long lean central hulls and short empty amas. Not the LEENs. One needs a very long central hull to decrease risk of pitchpoling and again weight is an issue.Still the LEENs offer a great cruising interior and achieve category “A”. Tenants designs seem to allow some weight to allow a cruising lifestyle but looking at the designs would seem to be prone to issues going to weather in a seaway. Have no experience on power cats beyond small center consoles for fishing. Would be quite interested in others experience.

 

[Marco Flamingo]

So what were your measurements?

The largest roll I saw was 5.1 degrees (not enough to knock over a pop can), but I was preparing myself for worse while watching the approaching wakes. It was the setup for throwing stuff on the floor. But the ART stifled it fairly effectively. It would start out as the old port/starboard/port roll building. That's when you look out and see that there are 3-4 more big waves coming. While an ART probably does have a "tuned" sweet spot, it tends to dampen from the beginning, and then (for my experiment) when a 5 degree roll comes, the roll is stalled a little, the roll back is only a 4 instead of building to 7 degree, then a 3, then the hull doesn't get back in sync while the rest of the wake passes, sometimes with just a final slap on the side of the hull.

I really, really wish my free inclinometer app had a recording/time function. My decibel and vibration apps both have that. For wakes, what it feels like is that the ART dampens the roll by modifying the roll period based on degree of inclination. A normal harmonic wave pattern can't do its mischief because the hull no longer plays a "single tune." At least that's what it feels like. There were times when it felt like "What? That's it? The whole wave train hasn't even passed yet."

The most pitch I saw was 2 degrees throughout the day, but I wasn't concentrating on that. In fact, I was trying to lay sideways to the various wakes.

 

[Mako]

Marco it would be good to take your measurements, then drain the bladder and take measurements again. great comparison on actual performance

 

[Marco Flamingo]

Marco it would be good to take your measurements, then drain the bladder and take measurements again. great comparison on actual performance

For anyone still following and interested in numbers rather than feelings, I did find an inexpensive recording inclinometer. $50 instead of a free app. It might give too many numbers. It is magnetic, so has to be mounted properly. It seems to be Android and PC. Biggest complaint seems to be that the "instructions" are standard Chinglish. But, for purposes of examining roll/pitch/yaw/degree/acceleration/period/decay, etc., it would (could?) provide actual data.

 

[Xlantic]

Maybe this app?

ClinoScope

toon|ClinoScope Support - toon,llc.

Have not tried it but it seems to record inclination over time.

 

[Marco Flamingo]

Maybe this app?

ClinoScope

toon|ClinoScope Support - toon,llc.

Have not tried it but it seems to record inclination over time.

That's the gadget, but for an iphone, which I don't have. If one looks at the "Time" section of the web page, it records the roll (of something) with the roll periods and magnitude. The roll that it shows stays the same magnitude for awhile but the period gets shorter. That would be a very nasty (and not likely) condition for a boat, but it does show that one would then have actual data to compare.

 

[Hippocampus]

What struck me as interesting about the SeaKeeper is the roll jus doesn’t seem to occur at all right from the beginning. No apparent latency to the effect. My limited experience is even active fins have a fraction of a second or so to act. Have yet experienced a strong beam wind to see if a sustained list occurs as some suggest. However been in gusty winds not a constant 20kts. However in 10-20kt seems not to. Suspect that varies with the boat.

 

[mvweebles]

What struck me as interesting about the SeaKeeper is the roll jus doesn’t seem to occur at all right from the beginning. No apparent latency to the effect. My limited experience is even active fins have a fraction of a second or so to act. Have yet experienced a strong beam wind to see if a sustained list occurs as some suggest. However been in gusty winds not a constant 20kts. However in 10-20kt seems not to. Suspect that varies with the boat.

Good point. Fins can sometimes have a short lag, sort of similar go a NYC subway that slightly jostles side-to-side.

I look forward to hitching a ride on a gyro-equipped boat someday. It's a cool system.

Peter

 

[Steve1.0]

What struck me as interesting about the SeaKeeper is the roll jus doesn’t seem to occur at all right from the beginning. No apparent latency to the effect. My limited experience is even active fins have a fraction of a second or so to act. Have yet experienced a strong beam wind to see if a sustained list occurs as some suggest. However been in gusty winds not a constant 20kts. However in 10-20kt seems not to. Suspect that varies with the boat.

I've run roughly a dozen boats with Seakeepers and their ability to keep a boat FLAT (roll wise) is impressive.

I recently did a day captain job for the new owner of a Sabre 58 (very rolly boats) equipped with one as well as ZipWake trim system. We made the loop out Palm Beach inlet and back in thru Jupiter with a 3-4' beam chop/swell.

The guests all had bubbly in champagne flutes sitting on tables, and not a drop was spilled.

The Seakeepers are very impressive, and heavy. This one takes 40+minutes to spin up.
On the other hand, during a delivery from Savannah to Stuart in a new 53 Riviera fly bridge, I had a different experience. We left St Augustine on the second day with 6-9' quartering seas from the NE. The seakeeper aboard overheated after about an hour, and went to stand by. The rolling became crazy. I was hanging onto the helm and console to keep from being tossed about bridge. Needless to say I called it, and came in Ponce inlet, finishing the trip in the ICW.



Overall, my limited experience with the SK's is very positive.


P.S. No affiliation with SeaKeeper. Just another delivery mule.

 

[cardude01]

That's one reason aft pilothouses are typically more comfortable than forward. It's a better placement and makes pitching motion much more tolerable. Of course, you're typically still up high, so rolling motion is rather noticeable.

The Pilothouse is pretty far aft on my boat, and the helm is just past amidships. When it gets really rough on crossings I will sit all the way aft in the pilothouse (with the steering on autopilot), and if I’m feeling sick outside in the cockpit for a few minutes is even better.

 

[libertas]

To stabilize or not

This has been a very interesting thread for me to read. New to the forum but an experienced boater/sailor, now moving to the dark side. Looking at both Defever 49 CPMY and Grand Banks 46 Classic. I know these boats are somewhat apples and oranges, one being a planning hull and the other a more displacement hull. one with twin 135's as standard and the other with 375's to 435's. I always thought that the slower you are going to go the more you will want stabilizers. There do not seem to be many GB 36 made with active fins, many more of the Defever's are.
Anyone seen a Seakeeper added to a Defever 49?? Aside from the space requirements sounds like it would work well. Maintenance??To
To the GB owners out there, how do the hard chines work out at anchor. Do they tend to be more suseptable to roll than the soft chine round bilge, KK, or Defever ect.??


Libertas
Future Trawler Owner
Past Tayana 52 owner

 

[mvweebles]

This has been a very interesting thread for me to read. New to the forum but an experienced boater/sailor, now moving to the dark side. Looking at both Defever 49 CPMY and Grand Banks 46 Classic. I know these boats are somewhat apples and oranges, one being a planning hull and the other a more displacement hull. one with twin 135's as standard and the other with 375's to 435's. I always thought that the slower you are going to go the more you will want stabilizers. There do not seem to be many GB 36 made with active fins, many more of the Defever's are.

Anyone seen a Seakeeper added to a Defever 49?? Aside from the space requirements sounds like it would work well. Maintenance??To

To the GB owners out there, how do the hard chines work out at anchor. Do they tend to be more suseptable to roll than the soft chine round bilge, KK, or Defever ect.??





Libertas

Future Trawler Owner

Past Tayana 52 owner

At anchor, very few boats have stabilization. Good news is relatively affordable to add. Forespar makes ourrigger poles. Ballpark guess is $5k. Not all cruising grounds are rolly so maybe that explains why few have flopper stoppers.

The GB46 and DF49 are more similar than not. Some folks like a pilothouse and small aft deck. Some like a social inside helm and flybridge. Both have a lot of teak. Both could take you from Alaska to Maine in relative comfort and similar costs. Both a couple cabins plus some room for a couple additional guests. PH layout tends to be a bit chopped up. Trunk cabin layout tends go not have great outside space except for flybdige. I personally like sedans but they probably have the least amount of accommodation space of all layouts.

I'm big on having some form of active stabilization when underway. If you're at the outset or your search, I'm sure you have a list of nice-to-have vs must-have. Stabilization is on my must-have list - its expensive and difficult to add. Better to let a previous owner take the hit on that one.

Good luck.

Peter