After dropping three more depth charges, the enemy warship continued to ping until after 1400.

The next night, she sighted another enemy warship, a destroyer or a torpedo boat.

In all they sunk 54 enemy warships.

Their essential role had not changed since the age of sail -- to serve on long-range missions, patrol for enemy warships and raid and defend commerce.

As their detection systems come on line, they detect two enemy warships.