Waveless Stab stabilizers

I don't appreciate the implication that by praising Sleipner one has a vested interest with them. It seems anytime one has an opinion you don't agree with you take shots at them. Please don't make accusations like that when one has an opinion different from yours. It's possible to respect another's opinion, even if you disagree with it.

I do praise Sleipner as does Capt J. I owned a Sunseeker Manhattan 65 with them and covered over 9000 nm in that boat. How much have you run a boat with Sleipner Vector Fins? Before buying I also tested the same boat with gyros. I've run similar sized and styled boats with Naiad and with ABT. I'm sure Capt J thought I was exaggerating until he ran a Sunseeker Manhattan 66 with them. I can't speak to all boats or all situations. I can simply say on the Manhattan 65 they performed exceptionally well and better than other systems on that boat. They did the job well at both speed and at anchor. There is no vested interest there. I thought before running them that the information was likely all hype. I was very pleasantly surprised.

I cannot speak to CMC. I have a lot of experience with Naiad and very good luck and know a lot of ABT fans, although some less certain since their acquisition. Our most recently purchased boat has Humphree Interceptors and Fins and I've been amazed at that combination. I saw the information but again can't tell how much is real. For instance, the talk about the fins rotating 360 degrees at anchor. Well, I don't know how much that does, but I know the system worked well at anchor. I will say they have some very impressive sea trials of Cranchi and Sunseeker on their web site. Now all they show also have their Interceptors so I don't know how one would know much of the Fins by themselves.

Like you, I am not a fan of gyros, especially on the boats under discussion. I do think one thing they have done. They've pushed others into really working on improvements to zero speed systems. As a result, I think you're seeing great improvements in fin systems which were already performing well at speed but now are doing so at anchor. I hope so, because I don't like the idea of having both fins and gyros on a boat and my favorite builder is doing that widely now. I think on fins we're going to see a typical technology situation where the one with the most recent introduction is slightly ahead until the next one jumps them.

My non scientific experience. The curved fins worked amazing on the 66' Manhattan. Unlike any other type of stabilization I've used, and I've used most all of the different brands. I believe the curved fins don't slow the boat down like large traditional zero speed fins. But I've also seen where they help with pitch at anchor.....now possibly it may be for other reasons such as pushing the boat forward a hair so the bow isn't bobbing on the anchor chain.....idk.....

There's one yacht I run a lot that performs worse at cruise 1/2 of the time with the gyro on, that 1/2 of the time I run it with the gyro locked.....the gyro is also undersized..........but anytime the waves are from the stern area.....think stern light degrees of the stern......it makes the boat flop on it's side when it rocks and it stays there at a list for 1-2 minutes at speed.

Gyro's generally shine at hull speed and below. They are also good in areas with a lot of debris and logs since you don't have anything protruding from the hull.

If someone is swimming, turn the stabilizers off!!!!! No different than having the engines off if someone is in the water.

Reviving this thread in hopes of getting an answer to the simple question… does anyone have first hand experience with CMC Waveless fins operating at anchor and at displacement speed (8-9 kn)? I am considering either a SeaKeeper 6 or the Waveless STAB 20 for our new NPY45 being built now.