If I go on a dive-trip I always carry an emergency kit with me.
Needle nose pliers
Small steel brush
Air gun for connecting to the LP hose adapter
Knife (Swiss army knife or Leatherman tool)
That all fits in an empty mask box or other small plastic container. If you don’t have space for bringing all that, make sure you have grease, super glue, duct tape and cable ties. You can fix almost everything with that!