The M400 is the first of the range with an entirely new look. It is a brand-new boat with nothing borrowed, except the very solid windscreen, which is found on all other Riviera models. It has a contemporary look, which is very evident below decks. But despite this it is a big volume boat with a big, gutsy profile.
The 13′ 7″ (4.13m) beam has been taken well forward to make use of any void space. In fact, there is no void space in the boat, every space that can be used has been. The result is a one level cockpit and helm station with a very large lounge area. There is a foldout dining table, using all the space of the aft section of the cockpit. The table was stainless steel grate inserts and stainless bottle and glass holders in the middle, and the aft lounge would seat about five people comfortably.