The Offshore Voyaging Reference Site

The "S" Word—Stability

From the first time I saw one, I thought that one day I’d like to own an OVNI for long distance cruising. Living and working for part of each year in France meant that I encountered OVNIs and their sisters from Garcia and other builders regularly, and saw them return battered but proud from distant shores again and again. Listening to their skippers only made me more envious—all of them had nothing but the highest regard for the seakeeping abilities of these quirky craft. One day, I thought, one day…

So when the time came to put our money where our mouth is, there was no hesitation. And I can honestly say that the vexed question of the supposedly limited stability of the OVNI was never an issue for us. I simply thought of Jimmy Cornell taking his OVNI 43 Aventura III to the Antarctic and Alaska, and then crewing aboard Igloo, an OVNI 39, to Spitsbergen. I also thought of many other well known high latitude boats, Pelagic, Seal, Parati (to name a few), all lifting keelers that have made equally illustrious voyages. Now, we’ve a long way to go before we dare to include ourselves in the company of these immensely capable boats and their crews, but you have to aspire to something. Nonetheless, I thought it would be interesting to check the numbers.

The OVNI 435 has an EU category A (Ocean) rating, and that’s good enough for most people over here. Being no naval architect, the complexity of the formulae needed to come up with comprehensible figures made my head spin, so when I heard about the excellent Sailing USA web pages, for example, where simple data entry can be calculated to give a wide variety of figures that might be pertinent to ocean cruisers, it seemed a good place to start. So using the manufacturer’s data from our owner’s handbook, the website allowed some basic calculations to be effected.

The OVNI 435 has a ballast ratio of 135%—about average for today’s cruising yachts, and has high form stability, as we found when we sailed her home recently. The stability value is 34.15, and the Angle of Vanishing Stability (AVS) is 126.57, within the boundaries deemed acceptable for ocean crossing. The capsize screening value is 1.84, anything less than 2 being considered good. So looking solely at the stability numbers there is little to be overly critical about.

In terms of performance and comfort, the OVNI shows up well. The displacement to length ratio is 258, firmly in the moderate category, whilst the sail area to displacement ratio (with the standard genoa) should provide more than enough power for fast passage making at 22.42—ours will be lower, though, as we are having a yankee rather than a genoa as our working headsail, giving us a rating of somewhere just under 20—more cruiser territory. And finally, she has a motion to comfort ratio of 31.17, which when combined with the soft ride associated with internal ballast should make her a comfortable boat to make long passages aboard. All in all, a steady, middle of the road design built for long distance cruising.

Of course, these are “dry” figures, so we’ll be making sure that we don’t overload our boat. She has been kept deliberately simple, and even with only two of us aboard for most of the time, we’ll still be watching the weight. We’ve also kept weight down aloft—radar on the stern arch, hanked on staysail and so forth to keep the stability levels up, and in keeping with all our previous boats, we’ll be stowing everything possible below decks on passage. Keep it low, keep it light and keep the decks clear is a good way to go, we believe.

Another factor we’ll be looking to exploit is the ability to lift the centreboard when going downwind, not just to gain extra speed (although that’s good, too) but to avoid “tripping” on the keel and broaching. Many experienced OVNI sailors report lifting the keel in bad weather, allowing the boat to slide when hit by bigger waves, rather like a multihull. Well, if and when we have to face that, we’ll find out how well it works!

But at the end of the day, these are all just figures, and as it’s not unknown for well respected ocean cruisers to get into serious trouble if caught in the wrong place at the wrong time, we’re not kidding ourselves that we’ll be any less likely to suffer if it’s our turn one day. And so we’ll be out as soon as possible learning how our new boat likes to heave-to, run or work her way upwind in strong winds, and what survival tactics or equipment will be most suitable for our boat, so that we’ve at least a good working idea of where to start when the going gets really tough. There’s nothing like empirical experience, as the sea soon deals with the complacent, and at the end of the day it’s down to the way the crew handle the boat in so many cases, and staying away from the most dangerous places and conditions if at all possible.

The Sailing USA website makes this abundantly clear, quoting the 1998 Sydney/Hobart race review report that gave the following as one of the significant findings:

There is no evidence that any particular style or design of boat fared better or worse in the conditions. The age of yacht, age of design, construction method, construction material, high or low stability, heavy or light displacement, or rig type were not determining factors. Whether or not a yacht was hit by an extreme wave was a matter of chance.

The numbers for the OVNI are reassuring, and may be one of the reasons why so many experienced sailors over here choose them for ocean crossings, which is good, but it is surely only a small part of the picture. We always felt we had chosen wisely long before we looked at the numbers though, and felt that as others had gone before us and come back to tell the tale, then with time, experience and humility in the face of the sea, maybe we shall make it too. So now it’s down to us, a good strong boat and yes, that indefinable entity—luck.

Inline Feedbacks
View all comments