[Graham Boak]

I don't recall mention of this, but suspect that it was variable, tied to the ship's commission. The crews would normally serve on the ship until it was withdrawn for repair, overhaul, or just having been a long time away. Then they would be posted to either another ship that was working up or (had the previous service been long) more likely a land base in a training role. This would perhaps depend upon their CO's reports.

There was also a system required to maintain full strength in units seeing intense action or overseas for a long time. Crews for the BPF did work up in Australia, presumably other similar theatres (eg India) had their own centres - Ceylon in this case. The potential therefore existed to allow some tour system, but again probably linked to the ship's operational cycle rather than any specific number of hours. Earlier in the war the low numbers of FAA airmen would restrict any such relief.