"We were diving in caves. It wasn't totally safe"

This quote by Jason Statham is describing a hazardous activity that he and others were taking part in. Diving in caverns is a dangerous venture, as the environment is often unforeseeable and can be hazardous. The quote suggests that the activity was not totally safe, suggesting that there were risks involved. This could imply that the caverns were not well-lit, or that the water was dirty and visibility was low. It might likewise indicate that the caverns were unsteady and might collapse anytime. Whatever the case, it is clear that the activity was not without its dangers. By acknowledging the risks, Jason Statham is showing that he knows the prospective risks and is taking the essential precautions to ensure his security.