The submarine did not sink any ships, but it did capture and bring back one German freighter of 1,127 gross register tons (GRT) in October 1915.

Kaiman and the other three boats of its class spent the rest of the war docked at Reval, in the Estonian Governorate, until the city was captured by the Germans in February 1918, at which point all four were taken to Germany for scrapping.

On 1 April 1905 Lake was given a contract by the Russian Navy to develop a new class based on the Osetr design but with more powerful weaponry and a longer range.

At first the Russian naval command intended for this new class to become part of its Pacific Fleet in case of another war with Japan, expecting them to be capable of reaching the Japanese coast.

[1] But by the time they were completed and entered service in 1911, Russian foreign policy had shifted from focusing on Japan back to Europe, where the Bosnian crisis in 1908 set Russia against Germany and Austria-Hungary.

[6] Emperor Nicholas II wanted to have submarines in the Baltic Sea that could help protect the Gulf of Finland and the maritime entrance to Saint Petersburg.

The Lake Torpedo Boat Company could not fix these issues but wanted the Russian Navy to accept them anyway, which it did, but without paying the final portion of the submarines' total cost of three million rubles.

Instead of paying the one million rubles that were still owed, the Ministry of the Navy used those funds to work on the design problems, and they authorized the submarine captains to make any changes to their boats that they deemed necessary.

The submarines were then sent to the shipyards in Reval to undergo changes, where a four-cylinder section from each of their two gasoline engines and the 47 mm (1.9 in) deck gun on the conning tower were removed, while new ballast pumps and two external Drzewiecki torpedo-launching collars were added.

[6] In the fall of 1914, Kaiman and the rest of the 2nd Squadron of the Baltic Fleet Submarine Brigade were transferred from Reval in Estonia to the Finnish island of Utö.

[7] During the first year of the war, the main role of submarines in the Baltic Sea was to defend the entrance to the Gulf of Finland (between Hanko and Dagö) by patrolling for German ships in predetermined positions and protecting Russian vessels laying minefields.

[7][8] Their operations were made more difficult by the cold climate causing much of the northern Baltic to freeze in the winter months, leading to a pause from about January to April.

On 10 August, a German force of three cruisers (Seydlitz, Von der Tann, and Moltke) along with some destroyers arrived off Utö and started firing their guns at the island.

Around this time the Russian Naval General Staff decided to change their strategy and ordered their submarines to target the shipping of iron ore from Sweden to Germany.