Two boats, one accommodation plan. Sunseeker's 76 Yacht and 88 Yacht both carry four cabins, four heads and crew quarters. If you shortlist by room count you will conclude they are the same boat at two sizes, and you will be wrong about what the money is doing.
Put the specifications side by side and the design argument falls out in one line.
The 76 Yacht: 77' 5" overall, 19' 6" beam, 5' 7" draft, 118,140 lbs at half load, 1,585 US gallons of fuel, up to 32 knots on twin MAN V12-1400s.
The 88 Yacht: 86' 7" overall, 21' 3" beam, 7' 0" draft, 170,417 lbs at half load, 2,907 US gallons of fuel, up to 28 knots on twin MTU 10V 2000 M96Ls.
Same four cabins. Same four heads. Same crew quarters. And 1,322 more gallons of fuel.
The step between the two is nine feet and two inches. Length overall is 86' 7"; Sunseeker names this class the 88. Quote the measured figure on a berth application, on an insurance schedule and in any comparison you build by length.
What the step buys
Fuel, beam and weight. Not bedrooms.
Fuel capacity goes from 1,585 gallons to 2,907. That is an 83 percent increase in tankage on a boat with an unchanged cabin and head count, and it is the clearest signal Sunseeker gives about what the 88 is for. This is the passage-making member of the pair.
Beam goes from 19' 6" to 21' 3", and half-load displacement from 118,140 lbs to 170,417. Volume at this length comes from beam and depth rather than from length, so the rooms are genuinely bigger even though there are the same number of them. Against the segment, 21' 3" sits close to the Princess X90 at 21' 8" and comfortably wider than the Ferretti 860 at 20' 5".
What you give back is speed and shallow water. Maximum falls from 32 knots to 28, tracking the extra 52,277 lbs. Draft goes from 5' 7" to 7' 0" at full load. Sixteen inches is not a rounding difference; on thin-water cruising grounds it is the entire decision, and the 76 wins it outright.
Settle the engine and the cruising numbers on the day
The installation is twin MTU 10V 2000 M96L. Take the rating as fitted from the yard, written onto your own contract, rather than from a listing.
Then take the numbers that matter more than the 28-knot maximum. Run the boat at the rpm you intend to cruise at, ask for observed burn at that rpm in writing, and work it against the 2,907 gallons under the floor. It is a fifteen-minute job on the day, and it describes your boat rather than a flat-water best case.
How it compares
The Princess X90 is 88' 11" on a 21' 8" beam, four cabins and four heads plus crew, 2,905 gallons of fuel, up to 27 knots on twin MAN V12-2000s. Two gallons and one knot separate the two boats. The Princess is longer and wider; the Sunseeker is quicker by a knot on the sheet.
The Ferretti 860 is 88' 5" on a 20' 5" beam with four guest cabins and two crew, 1,849 gallons, 28 knots standard and 31.5 optional. It is the narrowest boat in this group and the one carrying the least fuel.
The Azimut Grande 27M is 87' 10" on a 21' 7" beam, four or five cabins plus two crew, 2,510 gallons, 28 knots. The five-cabin option is the thing it can do that the Sunseeker cannot.
The water number
Fresh water on the 88 Yacht is 370 US gallons. The 76 Yacht carries exactly the same 370 while displacing 52,277 lbs less, and the 95 Yacht one step up carries 462.
Four cabins plus crew on 370 gallons means the watermaker, not the tank, is what keeps you off a dock. Establish its capacity and the storage arrangement at the order desk. It is a cheap conversation to have early and an expensive one to have late.
Four things to get in writing
The MTU rating as installed. Take it from the yard, on your contract, rather than from a listing.
Rigged weight and tankage as fitted. 170,417 lbs at half load and 2,907 gallons are the published figures. Confirm both against your hull.
Observed consumption at your cruising rpm. Only a sea trial produces it, and only if you go out planning to record it.
Watermaker capacity and the arrangement drawing for your hull. 370 gallons of fresh water for four cabins plus crew, and an arrangement confirmed against your own hull number rather than the model name.
The verdict
The 88 Yacht is a well-positioned boat in a segment where it matches its rivals on accommodation, beam and speed. Buy it because you want the 76 Yacht's household carried substantially further, on a wider and heavier hull. Settle the performance envelope where it is actually settled: at sea trial, in writing, on a loaded boat.