Gambia or Goa

Gambia or Goa

I'm in the UK and planning a trip in February or March next year. We're
early fifties, no children with us, quite fit. We can't decide between Goa
and the Gambia, never having been to either. Neither of us want to spend all
day every day on a beach but we like sight seeing, trying local restaurants,
one of us likes shopping (!) , diving (but don't wnat to spend all holiday
doing it).
Any recommendations between the two areas and which resorts within those
areas? Don't mind hiring a car unless it's ridiculously expensive.
Thanks everyone