With the increasing involvement in underwater operations, the Navy's requirements become even more specific after the Second World War: military watches had to remain underwater in extreme conditions for long periods of time. In 1954, two new references, the Ref.6152 and the Ref. 6154, were tested.

Some of today's models were inspired by them, as they incorporated some innovations designed to make the construction even more solid and resistant: the case is made from a single block with fixed handles, retaining the cushion shape, with more pronounced edges on the sides. They received a general aesthetic revision of the individual parts and adopted a screw-down winding crown, tubular cylindrical replacing the conical cylindrical of the historic Radiomir.

After careful analysis of the tests, some modifications were made and the definitive reference 6152 1 was born, also with reinforced lugs and made from solid steel from the same block as the case.