Will,
My DH has the pump and he was told by the trainer that there are certain times you have to disconnect the pump. The piece that inserts into you remains and you put a special cap on to seal it. You turn off the machine & take the 'pump' and the connecting hose off and put it somewhere safe and dry. You wouldn't wear the pump into the shower, beach, or at intimate times. Of course, you can only be disconnected for so long, since you are on a constant flow of short term insulin. He doesn't use any long term insulin at all.
If you are just walking around you can still keep the pump connected and have the clip attach to either your belt or waistband. The pump just can't get wet.
My DHs pump is about the size of a cell phone, he uses a cell phone pouch to connect it to his belt or waistband.
Hope that gives you an idea of what to expect.
Hope you have a wonderful vacation!
God bless. Alice.