Aug. 20, 2019 Operational Hospital Support Unit Bremerton trains with Air Force Activated Reserve Sailors assigned to Operational Health Support Unit (OHSU) Bremerton were joined by their Naval Hospital Bremerton (NHB) counterpart for joint exercise Tropic Halo alongside U.S. Air Force 446th Aeromedical Staging Squadron (ASTS) members at Joint Base Lewis McCord in Tacoma,