How to install a Halyard Aquadrive in a Contessa 32

Colin King shows how he fitted an antivibration system for smoother, quieter cruising and reduced wear on his yacht's engine and gearbox

- Colin King

Like many boat owners, I got increasingly fed up with the noise and vibration generated by my engine and gearbox, and was concerned about the possibility of damage to the gearbox bearings and seals. After a bit of research, I decided to fit a Halyard Aquadrive antivibration system which, by isolation of the engine from the hull structure, is promised to reduce cabin and cockpit noise and vibration by 50% or more.

I hope by sharing my installation method I can assist PBO readers with the fine detail that would be impossible for Halyard to cover in their otherwise excellent instructions which are obtainable on the internet at halyard.eu.com.

How it works

The Aquadrive principle is based on a fixed thrust bearing to take the longitudinal loads generated by the action of the propeller plus a double constant velocity connection between the thrust bearing and gearbox that caters for axial alignment. Firstly, the soft engine mounts isolate the engine from the hull.

Secondly, the constant velocity driveshaft absorbs engine vibrations and eliminates the need for accurate alignment.

Thirdly, the thrust unit, fastened on a load-bearing hull section, is promised to reduce stress on the transmission, on the engine mounts and bearings.

The Aquadrive is available in several different sizes depending on engine horsepower, normal engine revolutions per minute (rpm) and gearbox ratio.

Before ordering an Aquadrive it's sensible to contact several suppliers to compare price. My supplier was TW Marine Ltd (I have no connection to the company) and I sought their advice on which model would be most suitable.