The Russian Navy's Delta-IV Class Karelia nuclear submarine has begun sea trials following modernisation to improve its tactical and technical performance at Zvezdochka shipyard in the north of the country.
During the modernisation, which began in 2004, the vessel has improved in the areas of noise reduction, enemy ship and submarine tracking capabilities as well as survivability, according to en.rian.ru.
K-18 Karelia has been equipped with 16 Sineva RSM-54 missiles and is expected to join the Russian Navy's Northern Fleet by the end of 2009.
In addition to Karelia, four other Delta-IV Class submarines: the K-51 Verkhoturye, the K-84 Yekaterinburg, the K-114 Tula and the K-117 Bryansk have undergone a similar overhaul.
All seven Delta-IV Class submarines currently in service with the Russian Navy are deployed in the northern fleet.