In terms of personal security, the Canary Islands generally feels safe and nonthreatening. The main thing to be wary of is petty theft.
If caught in a rip tide in deep water, do not fight against it as you may rapidly, and dangerously, tire. It is more advisable to try to call for help and to go with the flow to conserve energy; the rip tide will take you further out to sea, but you should be able to swim back. Rip tide channels are quite narrow, so another technique is to gradually swim parallel to the shore when caught in a rip tide and you should escape it.