Ocean Alexander 420 Sundeck Yacht Search Stock & Used Yachts The 420 Sundeck is a flybridge boat from American builder Ocean Alexander. The 420 Sundeck is a yacht built from GRP, the planing hull design will reach a top speed of 18 knots. Read More Specs Length 42' 3" Materials GRP Hull & Superstructure Show Full Specs Hide Full Specs Full Specification Principal Characteristics Length overall 42' 3" Beam 13' 11" Draft (full load) 3' 2" Fuel capacity 300 Gallons Fresh Water capacity 150 Gallons Black water capacity 68 Gallons Max speed 18 Knots Hull GRP Superstructure GRP Engines & Performance Standard Option Cummins QSB6.7 425mhp QTY x 2 Performance 419 HP (312 Kw) each @ 3000 rpm Maximum Speed 18 knots Engine Details Show Full Specs Hide Full Specs