As long as you land and depart from the portal country (Bahamas), you don't need the TSA/FAA/ATC waiver (technically it is covered under a blanket waiver). So same procedures as always. For flights not to and from portal waiver required (91 or 135). For 135 ops in regard to Customs, have a Customs bond in place and the normal forms for clearing into US. Also the APIS submission program. NBAA web site has a link to the waiver form and # to fax/call and the APIS program.