Sealand Aviation has a long history of modifying floats for customers.
In 1997 Sealand modified 4930 floats under contract to Advanced Wing Technologies. This 5475 straight float has been STC'd on the AWT piston Beaver at 6000 pounds gross weight.
In 1999 Sealand modified 4930 amphibian floats into 5475 amphibs for the US Department of the Interior's Beaver -no FAA/DOT was required. The aircraft is typically operated to 7200 pounds.
In 2000 Sealand modified two sets of 4930 amphibs to 5475 amphibs for Arctic Sunwest's 6000 pound Turbo Beavers. The 5475 amphibs are presently LSTC'd to 6000 pounds on water and 5700 pounds on land with Cleveland wheels and brakes.
Sealand Aviation holds the STC for modification of 4580 floats to 5250 floats and for installation of the floats on a Beaver. The aircraft can be certified to 5600 pounds with the Viking Air gross weight kit.
Operators are extremely pleased with the upgrade. They report that the Beaver now lifts off the water at less than 50 miles an hour, with a noticeably shorter take off run.