The breaker box we built in 2013 to be able to connect to a US-style 50A 220V~ pedestal is a "SCAME" brand, double-insulated (square-within-a-square symbol), IP66-rated box, 8-gang. It's got a clear window that opens via latch action so one can access the breaker inside.
We use inside only a 2-gang 32A 400V~ breaker, "Schneider Electric" brand, model C60N.
This box has two pigtails. One connects to the 50A pedestal; on the other, you plug in the power cable coming from the boat.
IP66 rating means:
First digit (6): Dust tight — No ingress of dust; complete protection against contact (dust tight). A vacuum must be applied. Test duration of up to 8 hours based on air flow.
Second digit (6): Powerful water jets — Water projected in powerful jets (12.5 mm nozzle) against the enclosure from any direction shall have no harmful effects. Test duration: 1 minute per square meter for at least 3 minutes — Water volume: 100 litres per minute — Pressure: 100 kPa at distance of 3 m
In other words, this is a weather-resistant enclosure. If submerged, water will get in.
SM2K No. 350 (2002)
Under sail, Sardinia to Ponza