Talvin - a typical RAF SAR flight in UK has 2 airframes, between 8 and 10 pilots (2 pilot ops on Sea King), 4 - 5 radar operators and the same number of winchmen. This gives you between 4 and 5 full crews. The readiness state is 15 minutes from 0800 to 2200 and then 45 mins from 2200 to 0800, the crews sleep on the flight and take all their meals there.
The shift changeover time varies from flight to flight but the shift is for 24 hours (first standby) - the following day the next crew takes over and the offgoing crew become the second standby crew on 60 minutes readiness either on the flight or at home if they live close enough and they will normally do tasking/airtests/training as required. The second standby lasts until Evening Civil Twilight or 2200 which ever is the sooner.
Normally a crew will do a run of 3 first and second standby duties over 6 days before having some standdown/leave and on average a crew will do between 8 and 10 first and second standbys a month.
To support this we have have 3 shifts of up to 10 engineers who carry out all first and second line servicing/washing/see outs/refuels etc - they also work a 24 hour shift system.
During the shift the crew is allowed to complete up to 4 hours of training (usually 2 hours day and 2 hours night) and after that can only launch on Sarops.