How Can A Fractured Heel Bone Be Treated?

hi! my son broke his calcaneus about 2 1/2 weeks ago. he is 15 and in otherwise very good health. it was a clean fracture, straight, no displacement. the dr in the ER put a splint cast on, then 1 week later the orthopedist switched him to a boot, and no weight bearing. he said he can take it off whenever he is sitting around and sleeping and should do ROM with his ankle, etc. he has NO pain and very very little swelling. we are scheduled for another appointment in 3 weeks which will bring him to 6 weeks since the accident. My question is : can he go swimming? if he s careful not to knock his foot. And, is there any chance he can try to put some weight on his foot around week 4 1/2-5? thanks!!!