I'd not want to be without my cameras on any trip! Your equip will be safer on the ship than on shore. Enjoy!
It's been quite a while since I was there, but I doubt very much has changed...
There are some areas of Ensenada "off the beaten path", i.e. not the usual touristy areas downtown, that are pretty rough. Be a little careful if you go wandering around there carrying camera equip. Maybe keep to a small group of at least three or four if you walk, or take a cab recommended by one of the downtown hotels or restaurants.
Be prepared for street vendors, mostly women and children. "Chicle" means chewing gum. They'll want to sell you some!
Don't drink the local water... That includes any drinks made with it without boiling, any uncooked items like salads that are washed in it, even ice in drinks. Most of the touristy places only use purified bottled water for everything. Still, it never hurts to ask.