ICE/CBP use DES-XL & P025 DES-OFB/AES, and also Nextels a lot for near-shore operations along the great lakes. It would be nice to know what sort of "scrambling" the guy heard. Sometimes for joint operations with Canadian authorities they've had no choice but to use a VHF Marine channel, but if they've gotten sophisticated enough for both US & Canadian parties to use secure mode, they should be smart enough to use a channel outside of the marine band for it.That's marine channel 80, which is normally used for commercial use. US Customs/Border Patrol has been stepped up in the area recently. It's not impossible that they would be using this, but I'm not sure why.