Ocean Alexander’s 90 is a muscular motoryacht that can maneuver like a lightweight.
There are two ways you can build a boat: light or heavy. If you employ all the known tricks of weight savings, you can get a boat that goes faster on less fuel but that also can feel overly buoyant, and even tender enough to seem occasionally to be at the mercy of wind and wave. If you build heavy, you can end up with a vessel that’s more resistant to roll and can shoulder her way through a seaway, although you’ll pay for those abilities in higher fuel consumption and/or reduced speed and may find that because of her inertia and mass, this vessel is slow to respond to helm input.
Notice all of these characterizations are conditional, for the degree of compromise in both cases will be magnified according to the talents of the hull designer. There is no better example of this than the Ocean Alexander 90 Motor Yacht. She’s a big boat by any measure. Her LOA is actually over 91 feet and her beam is a generous 22 feet 5 inches. These dimensions reflect an emphasis on providing owner and guests with plenty of space. This is especially true of her side decks whose generous proportions do not feel as if they come at the price of interior room.
Her listed displacement of 209,000 pounds belies her vacuum-infusion lamination. Indeed when it comes to the layup, it appears that strenuous efforts have been made to take out excess weight without compromising strength in any way. But building a lightweight vessel was clearly not the primary objective, as you will readily note during a walk-through. There’s plenty of marble and granite and loads of full-size appliances, and the standard equipment list is nothing short of exhaustive. Not so obvious, however—at least until you’re underway—is the amount of sound-attenuation materials that contribute to that weight. Multiple insulation barriers, most containing lead laminate, watertight bulkheads, and flexible equipment mounts, all add to the 90’s 100-plus ton displacement.
Comfort and quiet were obviously what occupied the minds of the 90’s designers, and it certainly shows in the omnipresent spaciousness—even in the aft crew’s quarters—and low decibel readings underway in all occupied spaces. But the test numbers tell only part of the story; the other part is the vibration that you should feel in your feet—but don’t—as the big 1,920-horsepower MTU V-12s spool up (this engine package will not be available on future builds, since it’s not compliant with Tier 3 emissions standards). Instead there’s only a distant exhaust hum that never intrudes into conversation, even when standing on the aft deck.
It is underway that you also appreciate the 90’s heft. She feels uncommonly solid and monolithic—not a squeak or groan. And when you get her outside in open water and run her up to cruising speed you can’t help but marvel at how casually she shoulders aside chop and waves. Admittedly we had nothing more challenging than 3-footers on test day, but the ease with which the 90 dispatched them at more than 23 knots was nonetheless impressive.
Generating that kind of speed is a noteworthy accomplishment in a vessel of this size, and it comes without any apparent liabilities beyond fuel consumption. Stability, both at rest and underway, is excellent; there’s no discernible tendency to roll or yaw with the standard stabilizers off, and running trim is moderate—never exceeding 3.5 degrees, even during hard acceleration. It’s the kind of performance that both maximizes the comfort of passengers and minimizes the work required of the helmsman.
But it wasn’t until we returned from our sea trial and were headed to our slip that I appreciated just how well thought out this boat is. It was a blustery day, with gusts to 20 knots, and we had to wait for three bridges during our transit of the ICW. Convincing a 100-ton vessel with plenteous sail area to stay put until bridge-opening time required frequent use of the 90’s standard bow and stern thrusters. Fortunately they, along with the Maxwell windlass, are powered by a hydraulic system run off the engines, so overheating was not a concern as it might have been with electric thrusters. But then the whole system suddenly quit. (Later investigation implicated a problem with a program in the logic controller.)
So there we were, in a confined channel, trying to keep a big boat safely positioned using just gear selectors—and faced with the prospect of getting her to dock amid a considerable blow on the beam. All this required some ambitious throttle work and some extra help on the dock, but in the end the 90 slipped home with surprisingly little drama.
The reason she did was her instant response to gear engagements, and the reason for that was a combination of large (48 x 46) props and a big 3.0:1 reduction ratio. When engaged, the wheels bit instantly and really moved the boat. Now obviously, the chance of repeating a failure of both thrusters is small, but it is reassuring to know that the helmsman can maneuver the 90 with gears alone should he desire or have to. And since a big reduction turns props slower, there’s less vibration, something that frankly is probably more important to the owner of the 90. It just shows again how well thought out this boat’s hull and drive system are.
And it shows how well the designers have hewn to the principal design goals of this boat: The 90 is all about quiet, comfort, and luxury, and when you think about it, what’s more important in a motoryacht than that?
Conditions During Boat Test
Air temperature: 70°F; humidity: 55%; seas 3′
Load During Boat Test
1,600 gal. fuel, 250 gal. water, 3 persons, 500 lb. gear.
Test Boat Specifications
- Test Engine: 2/1,920-hp MTU 12V2000 diesels
- Transmission/Ratio: ZF 3050A with 3.0:1 gear ratio
- Props: 48 x 46 4-blade Hung Shen NiBrAl
- Price as Tested: Upon request