Originally Posted by
chevvron
There are considerably more than 2 of the USMC operated ones in service.
Yes, HMX-1 (the Presidential flight) has around a dozen VH-3Ds. It's the only USMC squadron still operating the Sea King.
Originally Posted by
chevvron
There may also be some civilian operated ones in use in the UK for coastguard use but I'm not sure about that; I certainly saw one transitting eastbound on H3 a few weeks ago.
I don't believe the Coastguard operates anything so ancient, so the one you saw would probably have been one of the two heritage aircraft discussed above, or one of the aforementioned HeliOps machines (both of their airworthy ones are still on the military register).