The new Lagoon 400 offers:
- Balance between volume and performance, Saloon and cockpit, Cabins and washrooms, Accommodation and deck spaces.

Also the harmony of soft lines reminiscent of the Lagoon 410's simplicity and inspired by the Lagoon 620's charm and elegance.

The deck space, its strong points:
- Hard top bimini in line with the cabin top for a better protection from the sun (streamlined, more aesthetic).
- Easier to move around the stern, offering more shelter.
- Easier access to the dinghy via the transoms
- Flush deck hatches.
- Moving around more safely (no step exceeds 220 mm).
- Open cockpit for socializing.
- Direct communication between cockpit and galley.
- All controls brought back to the helm station.

The accommodation's strong points:
- Optimal practicality.
- Maximum light in saloon and cabins.
- Ventilation adapted to each area of the boat.
- Saloon design inspired by the success of the Lagoons 420 and 440 where the galley is between the salon and the cockpit.
- Unusual concept in the forward cabin(s) where the double bed can be converted into twin beds.
- Perspex shower screens in the washrooms.