You have a Saturday, eight people who said yes, and a stretch of water forty minutes away. What you do not have is a captain, a crew, or any interest in spending the morning explaining the plan to someone else. That is the boat the Sea Ray SLX 310 is built for — and it makes one deliberate choice that separates it from almost everything else in the 31-foot bracket.
It keeps its engines inside the boat.
Who It's For
The SLX 310 suits the owner who runs a full social calendar on the water and values deck space over cabin space. Eight to ten people fit without anyone sitting in someone's lap. There is a head compartment for the practical necessities and a 20-gallon holding tank behind it, but Sea Ray publishes no berth count for this model and does not pretend it is a weekender. This is a day boat with manners.
It is not a fishing platform and not a watersports specialist. If your ideal day is anchoring in a cove for three hours with a rotating cast of guests, the layout is aimed squarely at you.
The sterndrive configuration matters most to buyers who want the transom clear. With the drives tucked under the boat, the swim platform runs full width and nobody climbs over machinery to reach the water.
Design & Layout
The cockpit is the argument. An expansive social area with a standard wet bar — standard, not an upcharge — positioned within reach of both the helm and the seating. The aft-facing lounger converts to a sunpad at the water's edge, which is where people end up anyway.
Bow seating is deep enough for adults to stay comfortable underway, with double-stitched diamond upholstery in premium marine-grade vinyl. Optional bow filler cushions turn the forward section into a full sunpad at anchor, and a fiberglass bow side table with dedicated storage is on the option list.
The helm comes with dual 9-inch Simrad Glass Dash displays — 12-inch optional — carrying Mercury VesselView Link engine data, chartplotting, depth and fishfinder. The SmartCraft Digital Throttle and Shift system handles the controls, and Joystick Piloting comes as part of the standard propulsion package, which turns docking a 31-footer in a crowded marina into a non-event.
Performance
Standard power is twin Mercury MerCruiser 4.5L MPI ECT engines on Bravo Three drives, 250 hp each. The option list runs through the 6.2L at 300 hp and 350 hp per side, with SeaCore closed-cooling available on several of those combinations for salt-water owners.
Sea Ray publishes a wide-open throttle range of 44 to 50 mph for the SLX 310. That is the builder's own figure, and it is the only speed the builder publishes.
There is no published cruising speed and no published range for this model. Sea Ray's specification block gives length, beam, fuel, propulsion, draft up and down, dry weight, deadrise, water and holding tank, then a WOT band, and stops. Any cruise number or range figure you see quoted for an SLX 310 is somebody's estimate, including the ones that used to be on this page. We have removed them rather than dress them up.
What Sea Ray does publish is a 21-degree deadrise, and on a 31-foot dayboat that figure tells you more than a top speed would. Combined with the Quiet Ride hull — Sea Ray's hull architecture aimed at cutting noise and vibration — it is why the boat stays civilised in a chop that would have a flatter hull slapping.
The Bravo Three drives run counter-rotating props, which improves bite in turns and cuts torque steer. That shows up most in no-wake zones and beach landings, where predictability matters more than horsepower.
Ownership
The SLX 310 is owner-operated. No crew, no captain's licence, no systems that demand a professional on retainer.
The honest cost of the sterndrive choice is maintenance. Bellows inspection, gimbal bearing service and drive work are annual realities that outboard owners do not have. In salt water, the SeaCore package — closed cooling and corrosion-resistant components — is worth serious consideration rather than being an afterthought.
The counterweight is coverage. The SLX 310 is an SLX Sport Boat, which puts it under Sea Ray's five-year SURPA5S+ bow-to-stern warranty, plus a Limited Lifetime Structural Hull/Deck warranty to the original owner. Worth knowing: the SLX 400 and SLX 400 Outboard are explicitly excluded from that scheme and carry the three-year Sundancer terms instead. The 310 gets the longer one.
Where to Start
Sea-trial it against an outboard boat the same length on the same day. The difference you are buying is the transom and the ride, and neither shows up in a brochure. Then ask the dealer to run it at your real cruising speed and read the fuel flow off the screen — because that is the one number Sea Ray has not published for you.
Talk it through with us: TS@MintedYachts.com, +1 (404) 805-9819, or the form on this page.