I'm farely new to boating. Question for seasoned skippers.I sank the trailer wheels and lights as far back as I could and boat would still not come off trailer. An adult pushed from the bow, another adult pulled boat deck line tied to back cleat,cable unhooked from stem eye, no other tiedowns, stern and propeller were in the water,attempted to reverse with sufficient trottle and boat would not come off trailer! Trailer side rail guides was not the problem. Only thing I can think of is that the rollers may be stuck! I even tried three different launching docks! Help anyone? Persistantly trying.Thanks for any suggestions short of having another boat pull boat off trailer.