Depends.
First question. What does your employer require? Regardless of what we say here, if they require an ML, then thats what you need.
In general, if you are taking out young people 17 years of age or below, even where you do not strictly need to comply with AALA regulations, its probably a good idea to do so- if anything goes wrong its a good defence
so
if you are going to an area with an altitude of 600m or less and within 1/2 hour of shelter and or a metalled road capable of carrying a normal ambulance then the BST BEL award will probably suffice. here and open the link inside for operating remit
if you are going higher or into more difficult terrain you will need to think about a WGL or ML.
Some employers just blanket the requirment for an ML - on the basis that it is possible for ML terrain to occur at any altitude (steep ground for insstance).
