The mutual one i did was just BOSIET plus Norwegian waters training (hence mutually recognized) as far as i know they are the same just a little bit extra added on the end.
BOISET and its follow on FOET are both recognised practically everywhere (apart from wind farm work who say "yes but have you done your helicopter escape training" because they have no idean what BOISET or FOET is until you tell them to look it up!)