I have an 08 Sanger V215 with built in hard tanks in the rear. I want to add more weight to surf. I have a launch pad 440 bow sac, 150 sac, and 85 block that I fill with the Uber pump. I like the fly high mastercraft X2 sac (18x20x32: 455LBS), but I am not sure about the fittings. I am also not sure how big my rear locker is with the hard tank back there (forgot to measure before putting in storage today). The above sac should fit. I would like to use my one pump to save money and possibly eventually plumb it into the built-in system. So my questions are as follows: anyone know how big my rear locker is, will my pump work with the fly high sac, what fittings would I use, and are there any other bags you guys would recommend as opposed to the above similar size? Thanks!! <BR> <BR>Also, how are u sanger v215 guys weighing your boat for the best port side surfing.