Be aware and don't make bad choices is good advice. But, if you think the current wave of violent murders in Cozumel are limited to a few bad neighborhoods, you are wrong. There have been several shootings well within the area frequented by tourists and during the daytime (on the Malecon, in front of Chedraui, and in a nice restaurant on Avenida 15). I am not sure how you avoid a spray of bullets aimed at someone else if they happen to be close enough to you that bullets that miss them come at you. This unfortunate circumstance has happened to several tourists on the mainland (in Tulum, Playa, and Cancun)