The apex "aquabus" USB cables are the same as regular USB cables as long as the cable has NO "repeaters" or "signal boosters" built into the cable. I have been using 15 ft extension cables from startech for years without issue. Same ones as these except mine are 15ft.
http://www.startech.com/ca/m/Cables/...A-A~USBEXTAA10
Btw I was told this by a guy from tech support at Neptune systems.