Diamantina's stable hull and ASDIC dome in dry dock

The River-class hull is contrasted with the finer, more flared form of a destroyer or sloop. Its broad, nearly flat-bottomed form favors stability, strength, and straightforward construction over high speed. The bow still has enough shaping to work efficiently at sea, but the almost vertical sides advertise merchant-yard practicality. The visible ASDIC dome reveals the physical scale of the frigate's underwater sensor fit. A raised forward 4-inch gun and supporting weapons gave useful arcs against submarines, aircraft, and light surface threats in contested waters. Robust shafting completes the picture of an escort designed to keep working rather than chase destroyer performance.