You have found the boat. Thirty-one feet, Sea Ray, SLX 310, the numbers are on the page and you have read them twice. Then you walk the dock at the boat show and there are two of them, both badged SLX 310, and they are visibly not the same size.
They are not. Sea Ray builds two boats under that number, and if you are shopping the outboard you need a different spec sheet than the one you have been reading.
Same Number, Different Boat
Here is the comparison, both figures taken from Sea Ray's own specification blocks on the two model pages:
| SLX 310 (sterndrive) | SLX 310 Outboard | |
|---|---|---|
| Length Overall | 31'6" | 33'10" |
| Beam | 10'3" | 10'3" |
| Dry Weight | 11,252 lb | 10,335 lb |
| Fuel Capacity | 130 gal | 158 gal |
| Draft, trim down | 38" | 32" |
| Draft, trim up | 28" | 25" |
| Standard power | Twin MerCruiser 4.5L on drives (T-250 hp) | Twin Mercury 300 Verado (T-300 hp) |
| Cruising Speed | not published | 33-39 mph |
| Wide Open Throttle | 44-50 mph | 54-61 mph |
| Range | not published | 187 mi cruise / 117 mi WOT |
Two feet four inches longer. Nine hundred and seventeen pounds lighter. Twenty-eight more gallons of fuel. A hundred more standard horsepower. The beam is identical at 10'3", and so is the tankage at 24 gallons of water and a 20-gallon holding tank — everything else is a different boat.
The length difference is the one to think hardest about, because you will pay for it every month. The beam has not changed, so the extra 2'4" is not extra room to sit in. Walk both cockpits at the show and measure what you actually get, then price the slip.
Who It's For
This is a day boat for someone who runs a real distance to get to the good water. Sea Ray publishes no berth count for it and does not present it as a weekender. There is a head compartment — Sea Ray's teak flooring option covers the swim platform, walkthrough and head — and there is 158 gallons of fuel, which is the number that tells you what kind of day it is designed for.
It suits the owner who wants outboard ownership specifically: nothing under the cockpit sole, no drives to service, no haul-out to inspect bellows. If you keep a boat in salt water year-round, that alone will decide it.
Design & Layout
The seating runs cockpit to bow in double-stitched diamond upholstery on premium marine-grade vinyl, laid out to convert between travelling and lounging rather than committing to one. Bow filler cushions turn the forward section into a sunpad at anchor. A fiberglass cockpit table with dedicated storage is available, as is a bow side table, both offered with teak overlay.
The helm carries dual Simrad Glass Dash displays, standard at 9 inches and optional at 12, with Mercury VesselView Link engine data, chartplotting, and depth and fishfinder capability. Joystick Piloting is part of the standard propulsion package, which on a 33-footer with two outboards is the difference between a crosswind side-tie being a manoeuvre and being an event.
Underneath it all is Quiet Ride, Sea Ray's hull technology aimed at cutting noise and vibration. On a boat you intend to hold at 35 mph for half an hour at a time, that is not a luxury feature — it is the difference between arriving relaxed and arriving deaf.
Performance
Standard propulsion is twin Mercury 300 Verado outboards with Joystick Piloting, T-300 hp. The option list runs to twin Mercury 350 Verado V10s and twin Mercury 400 Verado V10s, both with Joystick Piloting.
Sea Ray publishes a 33-39 mph cruising speed, a 54-61 mph wide-open throttle, and 187 miles of range at cruise, 117 miles at WOT on 158 gallons.
One important caveat: those figures belong to the standard twin 300s. Sea Ray publishes no speed and no range for the 350 or the 400 Verado packages, so if you are pricing the upgrade, understand that you are buying a step up in power that the builder has not quantified for you. Ask to run the exact configuration you intend to order.
The 21-degree deadrise is unchanged from the sterndrive, which is the honest answer to "does it ride the same" — the hull section is the same vee. What has changed is where the weight sits. At 10,335 pounds dry with the engines hung on the transom, the boat carries its mass differently from an 11,252-pound hull with drives tucked underneath, and the trim habits that suit one will not be identical on the other.
The 25-inch trim-up draft is a genuine outboard advantage: it is what lets a 33-footer nose into a sandbar and back out again.
Ownership
Outboards are the ownership argument here and it is a strong one. There is nothing under the cockpit sole. No bellows inspection, no gimbal bearing service, no drive work — the annual list a sterndrive owner budgets for simply does not exist, and the engines can be worked on standing up, in daylight, without a lift.
What you give up is the transom. Two cowlings and a bracket occupy the space where the sterndrive gives you a full-width swim platform, and if your day ends with four people in the water and a ladder that actually gets used, that is a real loss rather than a talking point. There is a swim platform here, and a walkthrough to reach it, but it is not the same clear expanse.
The SLX 310 Outboard is an SLX Sport Boat, so it carries Sea Ray's five-year SURPA5S+ bow-to-stern warranty plus a Limited Lifetime Structural Hull/Deck Warranty to the original owner.
Where to Start
Sea-trial it on the same day as the sterndrive SLX 310, on the same water, and end both runs by swimming off the back. That is the decision, and it is a preference rather than a right answer. Then hold Sea Ray's 33-to-39 mph cruise for a real stretch and read the fuel flow off the Simrad screen, so the published 187 miles becomes a number you have verified rather than one you have been handed.
Talk it through with us: TS@MintedYachts.com, +1 (404) 805-9819, or the form on this page.