LEGO® bicycles come in many colours and can be equipped with panniers and other cargo for touring or Brick Scouts can wear their backpacks (but that isn’t very comfortable). [BL:bicycles]
Boats come in all sizes from small rowboats to ocean-going container ships. The larger sized rowboat can be used to create a sailboat just the right size for a small group of Brick Scouts.
LEGO included canoes in several sets over the years in red and brown. Fitting minifigs inside can be tricky but the Brick Scouts pictured were installed using 1×2 plates and bricks instead of legs.
All school buses of LEGO must be built. Will post links to good examples soon.
LEGO skis are made in many different colours and can be used for both water or snow skis. Make sure to get enough ski poles for those alpine adventures.
Snowshoes come in a variety of colours.