Good drills are always essential, even when they’re (fortunately) not needed. With every skill I’ve acquired over the years (free-fall parachuting, SCUBA, etc) I’ve relentlessly practiced for the many things that can go wrong. As they say with firearms training: “experts practice to recover automatically from problems, amateurs practice to hit a paper target.” I’ve never understood how tourists can blithely go diving at a resort without even having taken the basic PADI Open Water certification. Apparently if you don’t know about bad stuff, it never happens to you…. (sigh).