If you want to take your dan buoy on an airline flight–to meet a boat, for instance–you should know that your dan buoy is substantially the same thing as an inflatable life jacket. The TSA suggests that it is permissible to carry inflatable life jackets on flights, both as carry on and as checked baggage. Ultimately, though, it is up to the individual airline to determine what its policy shall be. Contact your airline ahead of time and determine what is their policy on inflatable life jackets.
TSA guidelines,
Disabling Chemicals & Other Dangerous Items Carry On? Checked? Small compressed gas cartridges
(Up to 2 in life vests and 2 spares. The spares must accompany the life vests and presented as one unit)OK OK Prohibited Items:Disabling Chemicals & Other Dangerous Items
Leland Limited, Inc. also offers a page on preparing to fly with inflatable life jackets. As of publication of Leland’s page, they advised roughly half of carriers permit inflatable life jackets, half do not.
Suggestion
Pack your dan buoy in your checked baggage, with CO2 cylinder removed and placed into a ziploc bag. Add a note in the ziploc bag that says Uncharged
and tuck that ziploc bag into your luggage next to the dan buoy. If you can, document with whom you spoke, or what source told you traveling with the inflatable life jacket would be acceptable on your airline.
Other Resources
The US Sailing web site has more helpful information.