Hi Phone
The only rods of 7ft or less that I have ever owned (and still do) are a couple of very light spinning rods plus a light dropshotting rod; but I would find it almost impossible to use any of these rods to trot a light float straight along a glide or gully 15ft or more away from my bank and downstream in a straight line, let alone striking cleanly through a float as it journeyed downstream with the line lying on the surface behind it.
I have several different length and different strength float rods which I use when trotting for various fish species; 11ft, 12ft, 13ft, 14ft 6in, 15ft and for the very occasional time when I need to trot very tight along the far bank below the rod tip for big roach on a local stream or I’m float fishing in a deepish swim; an older 17ft/20ft float rod, but unless I were trotting in an exceptionally narrow and/or exceptionally overgrown brook I wouldn’t even consider using anything shorter than my 11ft rod when I’m trotting; and a 7 footer would definately not be my choice if I’m trotting. The rod length that I find the most useful on my local stream when I’m trotting is 13ft.
That 15ft 6in Sphere rod that Ian used looks just the ticket.
Keith