Yes you can. The IATA (International Air Transport Association) regulations allow for two inflatable type lifejackets, plus two replacement CO2 cylinders to be carried in either hand or checked-in baggage.
However, the authorities have left the final decision to individual airlines who have then deferred to each individual flight captain as to whether they comply with the regulations or not, so in reality it is down to the captain and the airport security staff, if they feel there is a security threat, to refuse to take the lifejackets.
In order to overcome this, you should notify the airline when booking the ticket so it can be entered into the ticket (electronically), that you will be carrying lifejackets and also if possible obtain written confirmation to obviate confusion at Check-in or Security.
Furthermore the national air transport authorities ask customers not to berate their call-centre staff as the problem lies solely with the individual airlines and you will need to get their permission.
The relevant IATA guidance is as follows
A. Relevant IATA Dangerous Goods by Air Regulations
IATA DG regulations state that a lifejacket fitted with no more than 2 cylinders and no more than 2 spare cartridges may be carried in carry-on or checked baggage with the approval of the aircraft operator. Although most individual airlines state their policies on carriage of cylinders on their websites, these policies are not being applied consistently by their staff.
Failure to declare hazardous material to the airline is a criminal offence. Even if airline policy is to accept the specific IATA guidance, any passenger may be denied boarding unless all cylinders have been removed from baggage and confiscated.
For full details see
- IATA Dangerous Goods Regulations; 57th edition, published 1st January 2016, Section 2.3.
- USA TSA: Prohibited Items | Transportation Security Administration
- FAA: Hazardous Materials Carried by Passengers and Crewmembers, November 25, 2015
It is also advisable to remove any CO2 cylinder from its firing head prior to checking in or passing through customs.