SAN DIEGO -- The U.S. Coast Guard's prosecution of a petty officer for crashing a patrol vessel into a pleasure boat on San Diego Bay last year, killing an 8-year-old boy, is a bid to duck responsibility and avoid liability, lawyers for the officer said Wednesday.

"The family is rightly suing the Coast Guard," said Lt. Cmdr. Andrew Myers, one of the military attorneys representing Petty Officer 3rd Class Paul Ramos. "It's in the Coast Guard's interest to blame my client."

The accusations were made during a preliminary hearing being held at Coast Guard district headquarters in the Bay Area.

According to Ramos' legal team, the Dec. 20 boat crash that killed third-grader Anthony DeWeese of Rancho Penasquitos was a tragic accident caused by poor training and supervision by the Coast Guard, as well as visibility design flaws in the involved 33-foot patrol vessel -- all brought out by holiday-season lighting on the harbor.

Ramos, one of four crew members charged in connection with the deadly accident, faces the most serious allegation in the case -- involuntary manslaughter.

The boy and his family were aboard a 24-foot Sea Ray with a dozen other people when the accident happened during the annual holiday Parade of Lights. Members of three families on the smaller boat have sued the Coast Guard.

The Coast Guard vessel was en route to aide a grounded boat.

Charged with negligent homicide are Petty Officer 2nd Class Ian Howell and Petty Officer 3rd Class Brittany Rasmussen. A fourth crewman, Petty Officer 3rd Class Lavelle Teague, faces lesser charges in separate proceedings.

Among other information that came to light during the second day of the hearing:

Video of tests by investigators showed visibility problems with the type of patrol boat involved in the collision. When the engine is running at 3,000 to 4,000 revolutions per minute, the bow of the vessel rides up, obscuring the pilot's line of sight. Lawyers for the defendants contend that the problem is widely known among Coast Guard boatswains. Three of the 33-footers operate regularly on San Diego Bay

Ramos told investigators that, about five seconds before the collision, he turned his head to ask a crew member to activate the vessel's siren and lights

Ramos said he was driving the boat at 18 mph at about 3,000 rpm, not the 20-40 knots estimated by some witnesses

At the time of the accident, Coast Guard officials in San Diego did not require boat crews to do risk evaluations before every mission

The hearing, known as an Article 32 proceeding, is taking place at the Alameda headquarters of Coast Guard District 11, which includes San Diego.