However, the ships where finally completed with for the time extremely large batteries.

The submarine served in the Swedish Navy for almost 30 years and was then sold to Singapore in 1997 together with its four sister ships.

HSwMS Sjöormen was renamed RSS Centurion and Singapore reacquired the boat on 28 May 1999.

After 11 years in the Republic of Singapore Navy, she was decommissioned on 11 March 2015 and scrapped.

Her fin and sail were preserved as a memorial at the Republic of Singapore Navy Museum.