Complex sentence: The Maritime Border Troops of the Russian Border Troops were the Coast Guard of the Soviet Union, it operated within the twelve-mile limit of Soviet territorial waters and was equipped with frigates and corvettes, fast patrol boats, hydrofoils, helicopters, and light aircraft.
Split into simpler sentences: The Maritime Border Troops of the Russian Border Troops operated within the twelve-mile limit of Soviet territorial waters. It was equipped with frigates and corvettes, fast patrol boats, hydrofoils, helicopters, and light aircraft.