Lesson learned -get a Nautilus Lifeline VHF radio (
be sure that your dive skiff/boat tender -whether Liveaboard or Land-based Dive Operations- have Marine VHF Radios to receive your distress call), or at least an emergency PLB stored in a dive canister:
McMurdo Dive Canister - Star Marine Depot
If you are a US Citizen, register your own PLB Beacon with NOAA -US Dept of Commerce:
NOAA - Search and Rescue Satellite Aided Tracking - Register Your Beacon
NOAA - Search and Rescue Satellite Aided Tracking - System Overview
For US Citizens, they will call your designated Emergency Contact Info (Family or Friend that you've told about your traveling/diving overseas, with copies in hand of your passport and itinerary) for assurance that a particular PLB activation is not a false alarm. Then the whole SAR process chain gets started. . .
If you've planned this smartly, your designated Emergency Contact should also be given contingency information to follow-up aggressively by calling the US State Department, and US Embassy 24 hr emergency contact phone numbers of the foreign country that you happen to be in at the time to get rescue efforts going "expeditiously".
Also recommend registering with the US State Dept Smart Traveler Program, and noting that you will have a PLB registered with NOAA. . .
Smart Traveler Enrollment Program
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For a 2010 Wreck Expedition to the WWII
Aircraft Carrier HMS Hermes off of east coast Sri Lanka, along with the waist belt mounted
McMurdo Fastfind 210 PLB in Dive Canister, I brought a
Halcyon Diver's Life Raft folded & stowed in a butt mounted backplate pouch, and a
Deep Sea Supply Hydration Pack mounted between the twinset cylinders.
We did a lot of drifting decompression diving, and if the dive skiff (which did not have a VHF radio) lost sight of your SMB, you were essentially adrift in the Indian Ocean -->next land mass to the west being Madagascar some 3000 miles away. . .