A PWC collision on the river

May 1, 2007 by

GEI was assigned to inspect and report on a collision between a boat and a Personal Water Craft (PWC) on the Colorado River.

The boat was an eleven-year-old Glastron Sierra, a bow rider or open seating bow.The boat was reportedly traveling at about 20 miles per hour (mph) at the time of the collision, and was towing a skier.

The PWC involved was a four-year-old Sea Doo, GTX.   The top speed of this craft is estimated at 50-55 mph.  The speed of the Sea Doo at the time of impact was estimated by witnesses as at least 40 mph.

The boat was north bound; the PWC was south bound.  The boat was on the right side; the PWC was on “his” left side.

The damage to the PWC was indicative of the PWC trying to “cross the bow” of the boat, i.e., a left to right crossing when viewed from the boat.   As such, Inland Navigation Rules, Rule 15 required the boat as the stand-on vessel to maintain course and speed and the PWC as the give-way vessel to maneuver to avoid.

The PWC impacted the boat at about the 11 o’clock position, 12 o’clock being straight ahead.

At impact the PWC was driven under the boat due to the inward velocity rather than pushed out to the side by contact with the steeply angled bow.   The PWC also struck the lower unit (out drive) as it was driven under.   The skier testified that the PWC and the operator came up from beneath the boat.

A PWC is considered a Class A inboard boat by the U.S. Coast Guard.   As such it is expected to follow and obey all applicable boating rules and regulations.   Accordingly, both vessels or boats were subject to the general boating laws as well as any specific local laws applying to any particular craft.  The Inland Navigation Rules of 1980 apply on the Colorado River.   Up river traffic is generally required to be on the right side of the river, down river traffic also on “their” right side, i.e., the other side of the river.   The accident happened on the eastern side of the river approximately 1/4 of the river’s width from the bank.

Arizona Statute, section 5-350, states that it is prima facie evidence of reckless operation of a personal water craft if … it is operated within a zone of proximity to another watercraft closer than 60 feet … and …that within a zone of proximity to another watercraft closer than 60 feet, … it maneuvers quickly, turns sharply or swerves …

Based on a two vessel closing speed of approximately 60 mph (40 + 20), the closing rate was 88 feet per second.   Thus, a football field length of 100 yards is covered in about 3 and ½ seconds.   Normal perception – reaction time for a known function is taken as approximately 1 and 1/4 to 1 and ½ seconds.  One may conclude that the accident happened very quickly, with little time for maneuvering once the course was set.

At the last moment, seeing collision is eminent, both vessels are required to maneuver to avoid. The boat driver indicated she did not maneuver and was concerned for the safety of her skier (her ex-husband, but that is a different story).  She just had one other PWC in that party cross over and pass her on her right side; and was concerned about her closeness to the shore.  If the boat was about 75 feet from the shore, at 20 mph it would have hit the shore in approximately 2 and ½ seconds after turning in.   Had she turned sharply left, the skier would have had the PWC as an immediate, and most likely, deadly obstacle.

The Fort Mojave Tribal Police accident report indicated that an Indian Ranger verbally warned the PWC on a violation of spraying and operating a watercraft recklessly only 30 minutes before the accident.   The report continued by stating that the Ranger was just south of the accident area and saw the PWC attempting to cut in front of a boat … in an attempt to spray water on the occupants inside the boat.

The final factor in the accident was that the autopsy on the PWC operator reported a BAC exceeding the legal definition of intoxication.

This met the definition of a tragedy in all respects.