Kalran: Tales of the four nations/Submarine command

The Volksgard forces mainly involved ground forces. Additionally, their mountains has only one, if large, surface river with a network of underground rivers and water tunnels, providing a major natural obstacle to any sort of surface navy. As the result, the Dwarves navy was seriously under equipped. But as a sea force was quickly determined to be necessary, the ship must be small and dive underneath water tunnels was required. As submarines trade off increased construction costs for extra protection from air attack and long range detection, the Dwarves chose to focus of submarine warfare, at the cost of having no battleships.

How they are summoned is by having the commander requesting the Volksgard to send some naval support. Upon which a submarine will emerge from a shore closest to the base.