"Submarines, Battlefields and Betrayers: Military Stories on the Thames" will be the latest themed tours to be offered by the Thames River Heritage Park, starting July 20 and continuing through Aug. 25.

The 90-minute boat tour will deal with the role submarines have played here, from the Revolutionary War Battle of Groton Heights to the general role of the Navy and Coast Guard here. All the tours leave from City Pier behind New London’s Union Station. The tours on Saturdays leave at 4:30 p.m., while their Sunday counterparts depart at 3:30 p.m. Tickets are $20 for adults, $12 for children 12 and under, and may be obtained through www.thamesriverheritagepark.org.

Retired Navy Capt. Paul Whitescarver and former Groton City Mayor Marion Galbraith will narrate the first tour. The water taxis used in the tours are authentic Navy vessels, known as liberty launches that provided ship-to-shore transportation for sailors when they pulled into a port without docking facilities. Appropriately, one is named Groton, the other New London.