SAR is being maintained.
There will be two crews designated to cover SAR.
There will be a jet available.
Covec, I suggest you look at the stats - if a Nimrod SAR aircraft was always available, why would the National Standby Hercules be called in to help?
The SAR/Ops Nimrod MR2 was on operation standby at 60 minutes notice, with crews living in the mess, until about 2 years ago. When this changed to 120 minutes notice, crew members were then allowed to remain on-call from home. As has already been stated, some aircrew live as far away as Inverness.
The change was brought about to ease the burden on crews, post 2003, and was fought by the SAR Force. I'd like to bet that there have been times when a Nimrod has been requested to prove topcover for a helicopter but refused because of timing issues since the change to 2 hours notice.