General thoughts on Seakeeper Gyros?

Seems like it is a pretty amazing technology, though currently on the expensive side. Also takes up quite a bit of space and may be awkward to install.


On the other hand, given the right boat it could be a game changer. My wife and I would like to move into a boat that is more capable of longer offshore passages (think Florida to the southern and western Caribbean, not Atlantic crossing) in the next 5 or 6 years, but I don't want to add a lot of draft and I'd like to keep the ability to run 15 knots or so when needed. As you all know, not a lot of boats fit that bill, and those that do tend to be well beyond our price range of perhaps $350K.


Just for daydreaming, do you think an added Seakeeper brings more boats into this category? There are plenty of good unstabilized SD trawlers out there in the $250,000 range, so figuring on an extra $100 K for the gyro would it work?


Obviously, that wouldn't turn a mainship into a nordhaven, but would it make the Mona passage or the crossing from Cuba to the Yucatan more feasible/comfortable for a well maintained coastal cruiser?

In my mind, the 2 biggest problems are the power requirement and physical size of the thing. Plus there's the concern for how long it takes to come up to speed after powering it on.

rslifkin said:

In my mind, the 2 biggest problems are the power requirement and physical size of the thing. Plus there's the concern for how long it takes to come up to speed after powering it on.

Click to expand...

I wonder if the power requirements are such that you have to run the genset for it. That would be a mood breaker for me, but maybe not for bigger boats.

Ken E. said:

I wonder if the power requirements are such that you have to run the genset for it. That would be a mood breaker for me, but maybe not for bigger boats.

Click to expand...

For the bigger ones, yeah, I think it's in that category. For the smaller ones you could run it with big alternators and an inverter underway, but you'd still need the genset to run it at anchor.

For bigger cruising boats (as opposed to smaller center console fishing boats, where they are becoming very popular) you do have to run the generator. They came to fame for their ability to provide a very stable fishing platform when on the drift or slow troll. That, and the lack of hull protrusions. If you ever get the chance for a demo, take it, it is quite remarkable.

Yes, the generator run time is a bit of an issue. But in my mind it would be worth it for limited passages if they work as well as they say they do. We tend to run the generator at night for the AC anyway, so that also might not be a deal killer.


I wouldn't want to run it 24/7, but for when a swell comes in at night and starts rolling the boat to the gunnels? Yeah, I'd start up the noisemaker to make it stop and save moving the boat in the middle of the night to a more comfortable anchorage.

There are not a lot of 15 kt passage makers in the 40 - 55 foot range. What are you considering?

I think the addition of a Seakeeper would turn your Mainship 40T into a decent Caribbean Cruiser. The Caribbean doesn't require long distance self sufficiency, just stability for decent passages between the islands.

David

Shrew said:

There are not a lot of 15 kt passage makers in the 40 - 55 foot range. What are you considering?

Click to expand...

We are a ways off still. If I could afford it, I'd buy a Krogen Express, but they are out of our price range. We spend a lot of time in the Bahamas where I enjoy squeezing into very shallow, remote anchorages, so I would like to keep the draft at 4' or under. Also, after a boat with a lot of exterior teak (Gulfstar 36) and then our current boat with no exterior teak, I'll never go down the exterior wood trail again. Teak decks are an absolute deal breaker. This eliminates a lot of older boats and narrows the choices a surprising amount.

DavidM said:

I think the addition of a Seakeeper would turn your Mainship 40T into a decent Caribbean Cruiser. The Caribbean doesn't require long distance self sufficiency, just stability for decent passages between the islands.

David

Click to expand...

I've thought about that too. I wonder where you could mount it? I'd hate to give up all that laz space and generator access is hard enough as it is. Maybe between the engines?


Also, the 400 is a little stern heavy, IMO. I wouldn't want to put a lot more weight aft.

Unless at-anchor stabilization (or drift fishing) is your primary goal, I'd stick with fins. I think you get better performance, less interior space consumption, and probably less power consumption.

I did not have the space for the gyro type of stabilizers so I went with the fins. The unit runs from the engine. Unfortunately it doesn't work at anchor but I've never noticed any roll while at anchor and that is what I do 99% of the time. The one time that I was uncomfortable with rolling was when I hooked up to a mooring ball. I don't know why that would make a difference.

Maybe consider paravanes? You could mount to a 15 kt boat and use them when it's lumpy and you probably need to go slow anyway. Would double as flopper stoppers at anchor. Plus side is they are a fraction of the cost of gyro and take up no space so opens up a lot of boats in your price range. Downside is it's an unusual solution. Might want to stick to fast trawler types where the paravanes don't look hokey. Something like a Grand Banks with larger engines.

Dougcole said:

Seems like it is a pretty amazing technology, though currently on the expensive side. Also takes up quite a bit of space and may be awkward to install.
...

Click to expand...

Not sure what is "amazing" about the technology. The idea of gyroscopic stabilization has been around for quite a long time.

First gyro stabilizers on ships occurred in 1917.

It seems that with gyro stabilizers in large waves your should actually turn them off because it interferes with the ship's roll response. This can result in the wave breaking over the ship instead of the ship rolling with the wave. In the case of a large gyro, if you suddenly need to turn it off, it might take some time for the gyro to spin down enough for the gyro effect to reduce so that the natural ship motion can occur. In the case of a SeaKeeper 2 or 3, the spin up time is 30-45 minutes, so I expect that the spin down time is at least that long.

I have no experience with the Seakeeper but I would assume that you could disengage the stabilization immediately. Just because it takes time to spin up it should not take time to disengage it. I would be surprised if it has to spin down to disengage.

Comodave said:

I have no experience with the Seakeeper but I would assume that you could disengage the stabilization immediately. Just because it takes time to spin up it should not take time to disengage it. I would be surprised if it has to spin down to disengage.

Click to expand...

Thinking about it, I would guess that there is probably some way to "un-clutch" it.

The challenge with the Seakeeper is figuring out where to put it on an existing boat.

In relative size terms try to think where you would put another generator on your boat, as they are about that size and weight.

I REALLY like the idea of gyro based stabilization, and have been all over my boat trying to figure out where to put one.

Not an easy task.

ksanders said:

The challenge with the Seakeeper is figuring out where to put it on an existing boat.

In relative size terms try to think where you would put another generator on your boat, as they are about that size and weight.

I REALLY like the idea of gyro based stabilization, and have been all over my boat trying to figure out where to put one.

Not an easy task.

Click to expand...

There probably isn’t anywhere on your 47 that it will fit. Also it takes quite a bit of structure to install them. I would love one except for the cost and size.

Dougcole said:

Seems like it is a pretty amazing technology, though currently on the expensive side. Also takes up quite a bit of space and may be awkward to install.


On the other hand, given the right boat it could be a game changer. My wife and I would like to move into a boat that is more capable of longer offshore passages (think Florida to the southern and western Caribbean, not Atlantic crossing) in the next 5 or 6 years, but I don't want to add a lot of draft and I'd like to keep the ability to run 15 knots or so when needed. As you all know, not a lot of boats fit that bill, and those that do tend to be well beyond our price range of perhaps $350K.


Just for daydreaming, do you think an added Seakeeper brings more boats into this category? There are plenty of good unstabilized SD trawlers out there in the $250,000 range, so figuring on an extra $100 K for the gyro would it work?


Obviously, that wouldn't turn a mainship into a nordhaven, but would it make the Mona passage or the crossing from Cuba to the Yucatan more feasible/comfortable for a well maintained coastal cruiser?

Click to expand...

You should check out Magnus effect stabilization. Cylindrical appendages rotate out perpendicular to the hull when needed and fold in against the hull when they are not necessary. They are easy to install, have much lower power consumption and work when underway or at anchor. They are said to be generally as effective as a Seakeeper.

They are an option on the Elling E4 we are considering.

https://www.dmsholland.com/en/stabilizers/magnusmaster-2/

It is my understanding these units have to have a genny for power. Most I have seen power up at the dock, then set sail.

I also came across this brand that offers stabilization in both A/C and D/C models and smaller units.

https://www.quickusastore.com/

If you were to consider fins, these are pneumatic and can be run from a simple power-takeoff air compressor. They have several advantages over Naiads, Trac, Wesmar, etc.

https://www.gyrogalestabilizers.com

Dougcole said:

I've thought about that too. I wonder where you could mount it? I'd hate to give up all that laz space and generator access is hard enough as it is. Maybe between the engines?


Also, the 400 is a little stern heavy, IMO. I wouldn't want to put a lot more weight aft.

Click to expand...

Suspect you'd get some really weird rock n roll with the unit all the way astern.

Would really want to look at whole-boat mass distribution and put it someplace mid-ships.

Amadeus said:

You should check out Magnus effect stabilization. Cylindrical appendages rotate out perpendicular to the hull when needed and fold in against the hull when they are not necessary. They are easy to install, have much lower power consumption and work when underway or at anchor. They are said to be generally as effective as a Seakeeper.

They are an option on the Elling E4 we are considering.

https://www.dmsholland.com/en/stabilizers/magnusmaster-2/

Click to expand...

Very interesting, thanks for sharing. I'd never heard of that method.

There are other anti roll methods, including the anti roll tank, such as used on the Roughwater 58 "Swan Song". Also building on the paravane, is the "flopper stopper". I used these very effectively for many years in open anchorages in S. Calif. Mexico and Central America.

I found very few anchorages in the Caribbean where rolling was an issue. Also we never had air conditioning. With open hatches, and good "wind scoops", the breeze constantly provided enough cooling.

The Sea Keeper requires some very substantial mounting structure, well tied into the boat. It is not an object you can just "place there". Engineering for the specific boat is essential.

I also would be concerned about finding a boat which would be suitable for the passage South, be able to make 15 knots, and still be an effective and efficient passage maker. I would put the extra $100,000 into a better boat/engines, anchoring gear etc.

The distance from Pt. San Antonio, Cuba, to the Yucatan is only about 100 miles. The Gulf Stream can run up to 6 knots in the straits. The North Coast of Cuba is not all that good cruising--the South Coast far better. Seas in these areas depend on wind, which depends on time of year. Small boats (drug runners etc) do make the voyage from Yucatan to the Keys (and stolen boats appear there). It is about 330 miles from Key West, (about 60 miles less from Dry Tortugas) to Isla Mujeres or 2 days at trawler speeds.

I had Seakeepers installed on two trawlers, each utilizing a naval architect to specify mounting structures. As long as the net result was a balanced boat, it mattered not where the unit was mounted. In my case both boats had the Seakeepers mounted in a stern lazzarette in the cockpit. In each case some rearrangement of ballast was required. Both installs reduced roll by 80%, on already stable platforms. While the gyro does take 45 minutes to get up to useful speed, the stabilization can be disconnected instantly from the control panel while the unit still spins at speed. I have since sold one of the boats and replaced it with a vessel with fin stabilizers, but prefer the Seakeeper overall, and both systems require gen set operation.

ssobol said:

Not sure what is "amazing" about the technology. The idea of gyroscopic stabilization has been around for quite a long time.

First gyro stabilizers on ships occurred in 1917.

Click to expand...

The breakthrough is that they keep the gyro relatively small and light by spinning it at very high rpms made possible only because it is housed in a vacuum chamber.

timb7734 said:

I had Seakeepers installed on two trawlers, each utilizing a naval architect to specify mounting structures. As long as the net result was a balanced boat, it mattered not where the unit was mounted. In my case both boats had the Seakeepers mounted in a stern lazzarette in the cockpit. In each case some rearrangement of ballast was required. Both installs reduced roll by 80%, on already stable platforms. While the gyro does take 45 minutes to get up to useful speed, the stabilization can be disconnected instantly from the control panel while the unit still spins at speed. I have since sold one of the boats and replaced it with a vessel with fin stabilizers, but prefer the Seakeeper overall, and both systems require gen set operation.

Click to expand...

Interesting. I’ve been going back and forth between Seakeeper and fins. I could never determine how Seakeeper worked at 8 knots. All the videos are at rest. Your input is valuable to me.

timb7734 said:

I have since sold one of the boats and replaced it with a vessel with fin stabilizers, but prefer the Seakeeper overall, and both systems require gen set operation.

Click to expand...

Did you mean engine operation? Fins, I believe, are almost universally hydraulically powered, usually by a pump mounted to one of the mains, but I suppose some pumps are take offs of one of the gensets.