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Old 03-13-2022, 01:41 AM   #1
SANAUH
Member
 
City: San Antonio
Vessel Name: Serengeti
Vessel Model: NPY 450
Join Date: Oct 2021
Posts: 15
Stabilizers - Gyro vs Electric Fin

While I realize this topic has been covered many times over, the question of gyro vs fins has new twist (pun intended) with the CMC’s introduction of an electric motor driven fin stabilizer for boats as small as 40’ (12m) (https://wavelessmarine.com/).

I am having an SD trawler built (NPY45) and stabilization is a must have. We will be living aboard full time and will limit our travels to coastal cruising (Great Loop and PNW/IP) with time also spent in the Bahamas. Want stabilization while cruising (almost always at displacement speeds) and while on the hook (when unable to find a protected anchorage). Current plan is to have a large LiFePO4 battery bank, very large second alternator (Balmar 98 Series 24V/220a), and 2x 5KVA inverters with the goal of not having to run the generator when operating the stabilizer system or the stateroom A/C (Mabru 12MBTU 12V/44a).

As I see it, advantages to the gyro is greater roll reduction (mfg claims 76-95%, all reported numbers while at zero speed) and no protrusions. Disadvantages include long spool up time (28min to stabilization, 42min to full speed), periodic maintenance, and constant power demand (1.0-2.3kW). Advantages to the fins are instant on, no maintenance, less space needed in engine room, and lower total power consumption (0-1kW/0.1avg underway, 0-2kW/0.25avg at anchor). CMC claims 66-81% roll reduction (lower underway / higher while at anchor). Disadvantages are hull protrusions and less roll reduction.

So, for those that have experience with the latest generation of fin stabilizers… how effective are they really at reducing roll at displacement speeds (8kN) and while at anchor? Should I be worried about things getting caught on the fins (lines, kelp, debris) or them being damaged while cruising in shallow waters (e.g. Great Loop) or in the PNW where you might bump into a log?

The gyro we are considering is the SeaKeeper 6.
The fins we are considering are the Waveless STAB 20
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