Definitely hatch covers on, It's amazing how much crap birds and mice can drag in, tried to buy a Stingray once and one hull would have weighed 200kg from the honeycomb. If your mates going to weld or grind, decks up, if birds are going to stand on top and repaint for you decks down. Take it as far as you can with the main sheet, then take it the last foot with the extra 4 ropes. When going up most of the weight is on the main beam the rear rope is just to take it up level, when near the top sway to one side tie of front and rear then do the other side, tie the mast next to it.