August 20, 2026
Sea Ray SLX 400: The One That Publishes a Speed
Sea Ray publishes a 47–50 mph wide-open-throttle band for the sterndrive SLX 400 and no speed at all for its outboard sister. At 39'9" and 2…
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Expert Review, Technical Specifications & Market Analysis
The Essentials
| Feature | Specifications |
|---|---|
| Overall Length | 39'9" |
| Beam | 12'1" |
| Draft | 44" drives down / 33" drives up |
| Displacement | 20,794 lb dry weight |
| Engines | Twin Mercury MerCruiser 8.2L MAG ECT on Bravo Three X SeaCore drives (T-430 hp / 321 kW) standard; twin MerCruiser 8.2L MAG HO ECT on Bravo Three X SeaCore with Joystick Propulsion (T-430 hp / 321 kW) optional |
| Fuel Capacity | 250 gal |
| Water Capacity | 50 gal |
| Cabins / Heads | Sleeps four — Sea Ray describes a queen-sized bed in the aft section and a forward bunk that converts to form a social gathering area; 28 gal holding tank. Sea Ray publishes no head or shower description for this model |
| Max Speed | 47–50 mph (Sea Ray's published wide-open throttle range) |
Source: Spec & Photos courtesy of Sea Ray. Specs verified by Tony Smith, USCG 100 Ton Master, on August 20, 2026.
Part of the Sea Ray SLX series — see how owners step up through the lineup.
Quick Verdict
- Sea Ray publishes a 47–50 mph wide-open-throttle band for this sterndrive and no speed at all for the SLX 400 Outboard — the rare case where the older drive type is the better-documented boat
- 39'9" overall, 20,794 lb dry, 250 gallons of fuel, 21° deadrise. The outboard model is a longer boat with a bigger tank; the two genuinely share only the 12'1" beam, the 50-gallon water tank, the 28-gallon holding tank and the deadrise
- Standard power is twin MerCruiser 8.2L MAG ECT on Bravo Three X SeaCore drives (T-430 hp). Joystick Propulsion arrives with the optional HO ECT package, not with the standard engines
- Nothing is bolted to the transom, so the platform behind the fold-down swim terrace is uninterrupted and the machinery weight sits low and inboard
- Quiet Ride is a hull-level noise and vibration measure rather than a trim option — listen for it on the trial, not in the brochure
- Sea Ray publishes no cruising speed, no range and no head or shower description for this model. Get all three answered on the sea trial
Our Take
Here is the part nobody expects. The sterndrive is the better-documented boat. Sea Ray puts a 47–50 mph wide-open-throttle band on the SLX 400's page and puts no speed whatsoever on the SLX 400 Outboard's. Usually it runs the other way round — the newer, flashier configuration gets the data and the older one gets left alone. If you are the kind of buyer who wants a number from the people who built the boat rather than from somebody else's stopwatch, that is worth real weight in the decision.
The two SLX 400s are not the same boat, and the specification blocks prove it. This one is 39'9" and 20,794 pounds dry on 250 gallons, drafting 44 inches with the drives down. The outboard is a longer boat with a bigger tank and a completely different power package. They share a beam, a deadrise angle, a water tank and a holding tank, and that is roughly where it ends. Anyone who tells you the outboard is the same boat with motors on the back has not read either page.
What I would go and look at in person is the accommodation. Sea Ray describes a queen aft and a forward bunk that converts, gives you a 28-gallon holding tank in the spec block, and then says nothing at all about the head. On a 40-foot boat carrying four people overnight, that is not a detail I would take on faith. Open the door, sit in it, and decide whether it is a compartment you would use or one you would merely tolerate. Everything else here — the Quiet Ride hull, the Bravo Three X drives with their counter-rotating props, the terrace — I am happy to recommend on the published numbers alone.
Official Sea Ray Premiere: Inside the Sea Ray SLX 400
Video courtesy of Sea Ray.
Sea Ray SLX 400 Photo Gallery
Photos courtesy of Sea Ray.
Sea Ray SLX 400 Articles & Guides
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Frequently Asked Questions
Does the Sea Ray SLX 400 come with Joystick Propulsion?
Not on the standard package. Sea Ray's standard propulsion for the SLX 400 is twin Mercury MerCruiser 8.2L MAG ECT engines on Bravo Three X SeaCore drives at 430 hp a side, without the joystick.
Joystick Propulsion arrives with the optional 8.2L MAG HO ECT package, also on Bravo Three X SeaCore drives and also rated at 430 hp a side. If joystick docking is on your list, price the optional package rather than assuming it is aboard the standard boat.
Does Sea Ray publish a speed for the SLX 400?
Yes — a 47 to 50 mph wide-open-throttle band, which makes this the better-documented of the two SLX 400s. Sea Ray publishes no speed at all for the SLX 400 Outboard, the reverse of the usual pattern where the newer configuration gets the data and the older one is left alone.
What Sea Ray does not publish for either boat is a cruising speed or a range, so read the band as a ceiling rather than a plan. Fuel capacity is 250 gallons, deadrise 21 degrees, and dry weight 20,794 pounds.
Where do you sleep on the Sea Ray SLX 400?
Sea Ray rates it at Sleeps: Four and describes a queen-sized bed in the aft section plus a forward bunk that converts to form a social gathering area. The specification block gives a 28-gallon holding tank, and a macerator appears on the option list.
What Sea Ray does not publish anywhere on this model's page is a head or shower description. On a 40-foot boat carrying four people overnight that is not a detail to take on faith — open the door on the sea trial and decide whether it is a compartment you would use or merely tolerate.
Is the Sea Ray SLX 400 the same boat as the SLX 400 Outboard?
No. The sterndrive SLX 400 is 39'9" and 20,794 pounds dry on 250 gallons, drawing 44 inches with the drives down and 33 up. The SLX 400 Outboard is 42'2" and 20,678 pounds dry on 375 gallons, drawing 45 and 32 inches, with triple Mercury 300 Verados standard or twin 600 Verado V12s optional.
Per Sea Ray's own specification blocks the two share only the 12'1" beam, 21 degrees of deadrise, 50 gallons of water, a 28-gallon holding tank, Yacht Certified capacity and a Sleeps: Four rating. Anyone describing the outboard as the same boat with motors on the back has not read either page.