Lloyd R. Roundtree Seaplane FacilityLloyd R. Roundtree Seaplane Facility Seaplane Base is a state-owned public-use seaplane base located in Petersburg, a city in the Petersburg Borough of the U.S. state of Alaska.Facilities and aircraftLloyd R. Roundtree Seaplane Facility has one landing area measuring 9,000 x 1,100 feet. For the 12-month period ending August 6, 1995, the airport had 7,900 aircraft operations, an average of 21 per day: 75% air taxi and 25% general aviation.