Stabilizers

[edward]

Are larger beam Hatteras motor yachts less prone to roll . LesS need for stabilization ? IE , the 54 , 56 , 58 ? Edward

 

[scottinsydney]

All boats will roll beam on to swell and in particular other boats' wakes when you are at anchor.

The height of the swell/wake and its frequency will determine the severity of the roll when a boat is anchored. Roll can be mitigated somewhat when under way by increasing speed or turning into the swell slightly.

However there is a point when even an 18.5' beam boat will lurch uncontrollably from side to side. I have been knocked off my feet when anchored by another large boat's wake.

Do stabilisers work underway?...absolutely. The difference is amazing. Older boats such as mine do not have a spot for a gyro stablisier. We removed the old Naiad 252s two years ago and replaced with the largest Vetus fin system possible.

Our next upgrade to the Vetus system is an electric hydraulic pump that will bypass the engine mounted hydraulic pump and provide reasonable dampening of roll when at anchor and genset is switched on.

 

[Pascal]

Stabs not only dampen the initial roll when you get that larger wave but they pretty much eliminate the counter roll which is what is really uncomfortable.

Scott, are you sure you won’t have to upgrade the fins and the software for the Vetus to work at rest?

 

[SKYCHENEY]

In my experience, the 18'2" beam MY's roll more than the 15'10" MY's. Both need stabilizers.

 

[racclarkson@gmail.com]

Didn’t mention are we talking MY or convertibles. Lower CG is lower roll.

 

[edward]

If you just putt around on protected rivers ( cocktail cruises) and waterways are stabs really necessary ? Maybe just offshore? Thanks, Edward

 

[Pascal]

If you just putt around on protected rivers ( cocktail cruises) and waterways are stabs really necessary ? Maybe just offshore? Thanks, Edward

No they re not needed in protected waters . Once you get used them you can’t go back. For 10 years I ran an non stabilized 70’ skylounge with both a jet ski and 15’ tender up top. Plus the spare wheels up there. Talk about top heavy. If I didn’t pick the right day to cross the stream or Tongue... I paid the price

 

[scottinsydney]

Hi Pascal,

I experimented soon after installing the Vetus system by going out in the ocean, putting boat in neutral and stabilisers on. The result was that the boat seemed to turn into the swell and take it head on. There was little rocking but the fins were moving vast amounts of water and their rear edges come 1' out the hull side. I guess the fins would be 2 times larger than the Naiad fins they replaced.

My next test was at anchor in the harbour with steady breeze on the nose. With stabilisers on the boat seemed not to roll as aggressively when a big boat went by. You certainly do not want swimmers going down the side of the boat when the fins are moving.

I am not saying that the Vetus system is as effective at rest as a 360 degree 24 volt Humpfree system or a Quick gyro system, but the Vetus software certainly seems to work reasonably well at anchor controlling the fins in their range of movement. It was explained to me that the Vetus digital gyro was like a potentiometer similar to that used in an iPhone.

Vetus has already designed the electric motor pump and one way valves and T's for me to plumb into the lines. It will need 1.5 gallons per minute flow and I think a 1.5hp motor which is easy for the 20kva Phasor genset.

 

[SKYCHENEY]

When you're buying a used boat of this age, why not find one that already has stabilizers? There will be little to no price difference in the used boat with or without. And if you buy the one without and decide later that you want to add them, you'll probably be spending an extra $50-60K+

 

[Passages]

^Yep, any boat you are looking at that DOES NOT have stabilizers is a $70k downward adjustment.

 

[edward]

I guess the gyro systems are much more expensive ? Edward