 The first naval battle took place on 1 December , near the island of Russarö , 5 km ( 3 @.@ 1 mi ) south of Hanko . That day , the weather was fair and the visibility excellent . The Finns spotted the Soviet cruiser Kirov and two destroyers . After the ships were at a range of 24 km ( 13 nmi ; 15 mi ) , the Finns opened fire with 234 mm ( 9 @.@ 2 in ) coastal guns . After five minutes of firing by four coastal guns , the cruiser had been damaged by near misses and retreated . The destroyers remained undamaged , but Kirov suffered 17 dead and 30 wounded . The Soviets already knew the locations of the Finnish coastal batteries , but were surprised by their range . 
