Non-emergent Ambulance job=what ever you can fit in the O2 bag (NRB, NC, O2 tank, basic wound care stuff) and a steth/BP cuff for calls going to the emergency room.
Waterpark first aid:
Fanny pack with a minimum of gloves/gauze/face mask which was carried around at all times. Basics could add to that from supplies as needed. For example, I had 4x4s, a petrol dressing, trauma pad, googles, gloves, mask, gown, icepack, triangle bandage, gauze, antibiotic cream, tape, and sting-eze. You can fit a fair amount in a bag with a bit of organization.
In addition, we had an Iron Duck back pack which carried pretty much everything found on your normal basic level ambulance sans transport equipment (e.g. back board) (O2 tank, NRB (ped and adult), NC (ped and adult), BVM (adult, ped, infant), wound supplies, cervical collar, small and medium cardboard splint, wound care supples, and a v-vac. In addition we had an AED in a hard case and an extra tackle box style trauma kit (only trauma supplies) that included mass casualty tags. I've often complained that the waterpark was more prepared to take care of patients than the ambulance was.
Equipment (bags, wheel chair, backboard, etc) was brought to a scene on an as needed basis. The only constant was the fanny pack.