I'm fairly new to sailing and i recently traded my old truck for a 21 foot santana sailboat, obviously i'm in need of a little adivice. First i was wandering what size motor(minium-maxium) i would need to push it on the river, the current is between 5-8 knots on average. Second i was wandering what the piece was called that attaches the boom to the mast, it seems to be missing on my mast. for now thats it,thanks.