 Complete the following phrase:  All navies of the sailing era kept a number of gunboats on hand. Gunboats saw extensive use in the Baltic Sea during the late 18th century as they were well-suited for the extensive coastal skerries and archipelagoes of Sweden, Finland and Russia. The rivalry between Sweden and Russia, in particular, led to an intense expansion of gunboat fleets and the development of new gunboat types. The two countries clashed during the Russo-Swedish war of 178890, a conflict that culminated in the massive 