Not a shipdriver, but an outside observer. Container mates seem to have the easier/easiest gig of various types of cargo haulers. Most of time is spent at sea doing what you went to school to do (drive a ship). Mates will not know what a wrench or a tool is, and maybe man a clipboard during cargo ops…but most likely in a USA port (and maybe foreign) they will be ashore drinking because a night mate came on to answer the radio questions.
Compare this with tanker mates, that don’t go ashore during cargo, and might actually swing valves and use wrenches at sea and have to stand cargo watch during cargo ops. Ironically, in the USA, box boats seem to pay the highest, and tankers lower. I’ve learned from foreign officers this is not the case in the rest of the world which is bulker<box<oil/product tanker<LNG. But, it’s all hearsay.