With correct training, supervision by experienced divers and attention to the guidelines laid down by BSAC, SCUBA Diving less hazardous than most other activity sports (you don’t need any training to ride a bicycle on public roads !).
However, it should be borne in mind that taking up sport diving may affect the validity of any life insurance policies taken out in respect of mortgages, loans etc., since it is still classed as a "hazardous" sporting activity by some insurers.
Membership of BSAC also provides third party liability insurance, currently up to two million pounds.