I was teaching a triox class in Key Largo a few years back when Chris Brown owned Silent World. Each day, I brought a typical Craftsman tool kit on the dive boat with lots of tools and dive stuff, including a spare analyzer, and all of the spare hoses and parts one might need for OC double tank diving. The divemaster would give me grief about it. I just didn't want a failure on the boat to ruin class. One day, the dive boat broke down. Turns out they didn't have a single screwdriver or wrench on board. The captain said, "Trace, please tell me you have that toolbox on board." I told him I did. He managed to fix the engine. He chastised the DM for always telling me to leave it behind. Scuba instructor = 1. Sea Tow = 0.