Koalatiger - when I was doing UK SAR, we carried maritime charts but they sat in a nav bag and were seldom referred to.
That was mainly because we knew our local areas - especially the lighthouses - and we had Admiralty charts in our operations room at the SAR flight.
I used to ask pilots questions about the charts during check rides.
Unfortunately, in a modern digital cockpit, any mapping will be electronic and few would see the need for including digitised maritime charts.
Coupled with that, they were operating away from their normal area and so were not as au fait with the letdown area as they might have been.