Editing Winter War (section)

===Coastal artillery===
Finnish coastal artillery batteries defended important harbours and naval bases. Most batteries were left over from the Imperial Russian period, with {{convert|152|mm|in|1|abbr=on}} guns being the most numerous. Finland attempted to modernise its old guns and installed a number of new batteries, the largest of which featured a {{convert|305|mm|in|1|abbr=on}} gun battery on the island of [[Kuivasaari]] in front of Helsinki, originally intended to block the Gulf of Finland to Soviet ships with the help of batteries on the Estonian side.<ref name="Lesk1999_130">[[#Lesk1999|Leskinen (1999)]], p. 130</ref>

The first naval battle occurred in the Gulf of Finland on 1 December, near the island of [[Russarö]], {{convert|5|km|mi|abbr=on}} south of [[Hanko, Finland|Hanko]]. That day, the weather was fair and visibility was excellent. The Finns spotted the Soviet cruiser {{Ship|Soviet cruiser|Kirov||2}} and two destroyers. When the ships were at a range of {{convert|24|km|nmi mi|abbr=on}}, the Finns opened fire with four {{convert|234|mm|in|1|abbr=on}} coastal guns. After five minutes of firing by the coastal guns, the cruiser had been damaged by near misses and retreated. The destroyers remained undamaged, but the ''Kirov'' suffered 17 dead and 30 wounded. The Soviets already knew the locations of the Finnish coastal batteries, but were surprised by their range.<ref name="Silvast">[[#Silvast|Silvast (1999)]], pp. 694–696</ref>

Coastal artillery had a greater effect on land by reinforcing defence in conjunction with army artillery. Two sets of fortress artillery made significant contributions to the early battles on the Karelian Isthmus and in Ladoga Karelia. These were located at [[Kaarnajoki]] on the Eastern Isthmus and at [[Mantsinsaari Island|Mantsi]] on the northeastern shore of Lake Ladoga. The fortress of [[Primorsk, Leningrad Oblast|Koivisto]] provided similar support from the southwestern coast of the Isthmus.<ref name="Tillo1993_152-153">[[#Tillotson1993|Tillotson (1993)]], pp. 152–153</ref>