There was a guy on our gated, roofed, floating dock that has 18 slips and and an end tie who constantly filled his diesel powered Trawler with fuel out of Jerry cans. It's not supposed to be done as per marina rules, but he never got sighted or questioned.
I don't think anything of bringing three new condition, non leak 5 gal gas cans (safely filled to only 4.5 gal each) to our boat for replnishment fuel on our 50 hp runabout during long weekends out and about. If there's gasoline remaining after filling runabout's two 6 gal tanks it goes into our Tolly's tanks... of course, that all is accomplished while on the hook, not at the dock.
I don't think anything of bringing three new condition, non leak 5 gal gas cans (safely filled to only 4.5 gal each) to our boat for replnishment fuel on our 50 hp runabout during long weekends out and about. If there's gasoline remaining after filling runabout's two 6 gal tanks it goes into our Tolly's tanks... of course, that all is accomplished while on the hook, not at the dock.