Kirsten Dunst’s boyfriend, Garrett Hedlund, wooed her with a romantic moonlight ride in a canoe. But it not-so-suavely capsized at 3 a.m. “It was not a stable canoe,” recalls Hedlund, who met Dunst on the set of “On the Road.” “We fell out and had to swim back in mucky, [bleepy] water . . . like golf-pond water.” But it worked: The actor’s been dating Dunst for a year. Hedlund further reveals in Details that he calls Dunst “my gal” and often hangs at SoHo bar the Ear Inn because it’s near her pad.