Resort Diving is mostly safe, the dive profile helps keep you safe. At 30ft, a lot less can go wrong. You can easily survive a rapid ascent from 30ft, heck you likely don't need to actively blow bubbles unless you took a huge breath or are ascending super fast. OP who hasn't dove in a while shouldn't make their first dive on vacation a 120ft bottom. They will likely not remember how to breath, how to swim and will consume too much air and blow the dive for everyone. I refuse to dive with strangers on dive boats, I have never once had a dive buddy physically verify my secondary and some of them get weird when I ask them to verify their primary and secondary with me. The 'I know' eye rolls when i show them where my weight release is, where things are on my BC. Honestly thats what pushed me in to technical diving, everyone takes it serious. If we do our math wrong and the drop tanks aren't sufficient or if the trimix was off we were all dead. When we did cave dives, knowing each exit, knowing the routes we were going to navigate. Rehearsing the transitions between lines. Even with the best planning, things go wrong. Read up on the Diepolder II and III caves - scary stuff