In reply to marzi:
as a self employed carpenter, if the odd time i am on day work for people (rare, much prefer price work), im working outside and it rains and i go home and dont work i obviously dont/cant charge the client. If i stay and go indoors to work or can work in and out of showers they get charged.
i think this is just a simple case of right and wrong. if ive got a guide or instructor and they call the day off for the weather i certainly wouldn't want to be paying them to have a day off chilling. if they decide we can work on nav, scramble, indoor wall ect ect then i have used their services and they get paid.
im pretty sure this is how most people would operate.. in my experience it has been. as already said, just discuss before hand and nobody gets upset