Not having a skilled crew member maintaining situational awareness on an actual chart will eventually get anyone in trouble. The statement the hazard is not marked would be correct. There are unmarked hazards all over the VI. Hazards are marked with yellow or a combination of yellow and black. A red buoy notes a channel, not a hazard. The skipper is guilty of loss of situational awareness. The unmarked hazard is clearly on the charts. There are many unmarked hazards in the area that are only visible with a chart.