A lawyer for the man who commanded the Coast Guard cutter Cuyahoga the night it sank in the Chesapeake Bay killing 11 crewmen accused the service yesterday of "deliberately" destroying "the biggest piece of evidence" in the criminal case against the ship's captain.

Attorney Jerome V. Flanagan told a military judge in Yorktown, Va., that the service should either raise the vessel or build a model of its bridge before the court-martial of Chief Warrant Officer Donald K. Robinson begins.

Robinson, 48, a career officer, is charged with involuntary manslaughter in the Oct. 20, 1978, collision of the cutter and an Argentine freighter near the mouth of the Potomac River.

The 52-year-old Cuyahoga, which sank minutes after being rammed by the freighter, was raised from the bay and later was sunk off the Virginia coast to form part of a fishing reef.

Flanagan demanded yesterday that the Coast Guard either raise the ship or build a full-scale mock-up of the ship's bridge, saying, "It is important that the persons who hear this case see for themselves the conditions that were on the bridge of the Cuyahoga that night."

According toa statement Robinson gave investigators shortly after the accident, he first thought the 525-foot coal freighter was a small fishing vessel travelling in the same direction as his ship.

Cmdr. R. A. Appelbaum, who will preside over Robinson's court-martial in June, took Flanagan's motions under advisement. Robinson delayed entering a plea to the charges until the motions are decided. Pretrial hearings in the case are scheduled to last until Friday.

Flanagan also asked that the Coast Guard investigation be reopened, saying the initial inquiry "was not an impartial affair."

In a separate finding, the National Transportation Safety Board earlier this year blamed Robinson - a 26-year Coast Guard veteran - for the collision. Although the Coast Guard released "findings of facts" that were almost identical to the NTSB's report, the service has not reported its conclusions from the initial inquiry.

If convicted of the manslaughter charge in the deaths of his crewmen, Robinson could be discharged from the service and sentenced to six years hard labor.

His June trial will be the first general court-martial since 1966 faced by a Coast Guard captain and the first trial of a Coast Guard skipper on manslaughter charges that resulted from a collision at sea. CAPTION: Picture, DONALD K. ROBINSON . . . former skipper of Cuyahoga