A double hull was used to minimise any chance of leakage.

A new, smaller, cast turret and redesigned rear hull were used.

A wooden hull can be used for operating models if properly sealed.

For the next 13 years, her hull was used for underwater rescue training.

Concrete hulls, reinforced with glass-fibre rather than steel, have been used in boat building for many years.

During the Siege of Leningrad her hull was used as a base for small ships.

The hull of the M3 was also used for self-propelled artillery and recovery vehicles.

From 1956 to late 1958, her hull was used for spare parts and experimental purposes.

A third hull, PG 142, was paid off and is used as spare.

The hull was used as a pontoon until at least 1937.