Many people I know are starting to go the route of a small trailer.
I haul 2-steel 100s, full bag of gear, float, DPV, cooler, clothes, etc. In the back of a Bravada. Times two, with my buddy and the thing is full with back seat down and it sinks REAL low in the rear end.
I have been seeing more and more of these single axel trailers that most vehicles can haul being used as portable equipment lockers.
You cant miss Mikes trailer!! It is bright red, painted as a dive flag and can regularly be seen traveling the roads of Northern Michigan. We have joked in that there is a dive charter operator based in Alpena that runs a Sea Ark that looks like a small landing craft and we keep threatening to put the trailer on the boat and it could not only serve all of our comforts but also double as the dive flag.
No more moving tanks from the LDS, to the car, to the garage, to the car, to the dive. His suits are all hung in the trailer that always doubles as a dressing room. He is capable of carrying up to 15 tanks (legally????). He even has two large equipment shelves that can double as sleeping bunks. This thing has been awesome to have around. Anyone with a hitch can haul it. The best thing is everything he owns is in it!! None of that left it at home stuff.
With my wife wanting to take up diving this summer I was torn to either buy a trailer or a RIB (Rigid hull Inflatable Boat). While the iron was hot, I got the boat, in case she changed her mind.