One rower was missing and three others were plucked from the Harlem River – one with a head injury – after their scull smashed into a power boat in the pre-dawn darkness yesterday.

The four members of a private rowing club had left from the Peter Jay Sharp Boathouse near Dyckman Street and the Harlem River Drive when the accident occurred between 5:45 and 6 a.m.

As they navigated a turn near 181st Street, their sleek scull collided with the 29-foot power boat, Inspector Michael Phipps said at a news conference at the scene.

Three of the rowers were fished out almost immediately by the operators of the leisure craft. One suffered a serious head wound and was listed in stable condition at Harlem Hospital. The injuries of the others were believed to be less serious.

The missing rower, identified by police as Manhattan resident Jim Runsdorf, 41, had been in the front seat of the scull. Divers from the Coast Guard and the police and fire departments continued their search hours after the crash.

Inspector Phipps said speed did not appear to be a factor in the accident, and he described the water as calm. “Visibility was more of an issue,” he said.

The motorboat also had left very early in the morning, when it was still dark, from Piermont in Rockland County and was heading for a marina in Connecti cut to be winterized, he said.

Although it was not immediately known how fast the powerboat was going, its fastest speed is 18 mph, Inspector Phipps said.

The scull, which was recovered by the rescue team, had one light on the bow but the inspector said that it would not have been enough for that time of day. It was not immediately known how many of the powerboat’s running lights were on.

The skipper of the motorboat was given a breathalyzer test and tested negative, Inspector Phipps said. Neither the skipper nor the other person aboard the motorboat was injured.