This page details our selection process for this project. For a look at the installation process, please click here.
Stabilizers are a common feature and in many cases a necessity on larger boats. In a nutshell, a stabilizer system works to reduce the roll of a boat caused by wave action and keep it – you guessed it – stable. The stability of a boat underway is obviously a comfort issue (particularly for those prone to seasickness), but it’s also a safety issue given how items and people can be tossed about. Rough seas are simply no fun and while stabilizers won’t completely eliminate a boat’s tendency to roll, they can help calm things down a great deal if they are well matched to the vessel. Stabilizers have been built into boats for decades with fin stabilizers (what we presently have) being the most ubiquitous and having changed little in how they work – until relatively recently. There are also new systems that have proliferated over recent years, taking advantage of advances in technology.
The short version of how fin stabilizers work is this: fins are mounted beneath the waterline and emerge laterally from each side of the hull. They’re controlled by a gyroscopic system that measures the boat’s rolling movement which sends that information through electronic controls which automatically change the fins’ angle to exert force to counteract the roll. Think of what happens when you’re in a kayak and you put the paddle into the water perpendicular to the way the water is flowing. The down-force causes the boat to begin a rolling motion. Fins on a boat produce lift that work against the roll movement of the vessel.
Why did we upgrade OLOH’s stabilizers? After a year of ownership and a few thousand nautical miles of cruising experience with her we identified her stability in beam (from the side) and following (from behind) seas as something that could be improved upon and increase our enjoyment of the boat. Our factory-installed WESMAR brand stabilizers did work but not as well as we feel they should for the way we like to travel. One of the reasons, per experts and general laws of physics, is that OLOH’s original fins were marginally sized for OLOH’s sixty feet, particularly for the speed at which we prefer to cruise (10 knots).
All of the options we explored would allow us to see a benefit from the modern tech that measures the boat’s movement and tells the stabilizers how to react. OLOH’s factory-installed (2004) system was analog and much more limited in its abilities versus the modern digital technology that the new systems employ. The new tech greatly enhances how well the system assesses motion and can be fine-tuned and adjusted beyond our original system’s capabilities.
Here are the systems we looked into…
WESMAR - Upgrade Fin Size And Technology
It didn’t take much research to learn that the simplest way to go about this project would be to work with what we had. The fins that were installed by the factory when OLOH was built were likely chosen for the boat’s optimal 18-knot cruise speed and less fin surface area is needed to provide stability at those higher speeds. Again, our preferred cruise speed is 10 knots. OLOH’s fins were 4.5 square feet minus the fiberglass that needed to be removed to miss hitting part of the hull as they swing. With the common thought being that we would see improvement in stability with larger fins we looked into what WESMAR could do for us. Between their larger fins working well with our existing gear and the new technology available with their modern control system this is an extremely viable and cost-effective option. We could have replaced our original fins with larger ones to see if the improvement was substantial enough before doing anything further -or- upgrade both the size of the fins and the electronics that control them for maximum impact.
- 7.5 square foot fins, which were being recommended to us, have the same shaft size as our original 4.5 sq ft fins (the shaft that the fin is attached to goes through the hull of the boat and is connected to the actuator inside the boat which moves the fin). We liked this as it’s never a bad thing to avoid making holes in your boat bigger. Also a big savings in time and cost.
- The entire job was expected to only take a few days which also helps to keep costs down. It was expected that the fins could likely be replaced in a day while the boat is already out of the water for scheduled maintenance. The new electronics can also usually be done in a day and the boat can be in the water when that takes place.
- The new gyro is a 3-axis system versus the boat’s original 2-axis system. Simply explained, the new gyro gathers a greater amount of information to read the boat’s movement much more precisely than the old setup giving more feedback to the electronic brain that tells the fins how to react. We were told this would improve the ride, especially in a following or quartering sea (which is where OLOH needs the most help).
- The new digital controller allows for a great deal more fine-tuning to better adapt the fins’ movement to our boat’s characteristics and has many setting options (versus our original system’s ability to only adjust sensitivity and trim). The new system can also be easily interfaced with OLOH’s electronics network to receive even more information (speed and position) to further enhance stability. A note for anyone with nearly any brand of fin stabilization looking to improve overall performance… WESMAR’s new, state-of-the-art electronic gyro and controller is a relatively easy, low-impact upgrade that is definitely worth looking into.
As far as larger fins further affecting performance because of increased drag, we were told by the experts that this will be negligible.
WESMAR has been wonderful to deal with and tremendously helpful from our first contact with them, connecting us with their distributor in Fort Lauderdale who reached out immediately to discuss our situation and make recommendations. We were then connected with Jim Monroe at Yacht Equipment and Parts in Fort Lauderdale whose team is WESMAR factory-trained and very well versed in their stabilizers having installed and serviced them for nearly twenty-five years. That’s the kind of experience you want on a job like this. Jim is a stand-up guy who has been a pleasure to work with, extremely knowledgeable and most generous with his time, getting on board OLOH to assess our current setup and answering any questions we’ve had. After a great deal of research and deliberation we were confident that, on balance, this was the right decision for us.