I know that with any transplant surgery you will need to commence a range of immuno-depresents (these are to ensure that your body does not attact your new knidney). With these types of medications you become very sensitive to sunlight. Basically by not wearing any suncream you will get burnt within the first couple of minutes of being in the sun. That could be a possible drawback seeing that scuba diving is an outdoors sport. Personally not too sure what else but would imagine you will need to first become well enough to resume such sports and wil need to wait unitll your body had healed from such majro surgery.