Half of the more than 10 million gallons of oil in Alaskan waters has dissipated, and much of what's left has been churned into a taffylike goo and tossed up on beaches, a state official said Friday.

"Exactly how that's going to be dealt with I don't know," said Bill Lamoreaux, an environmentalist with the Alaska Department of Environmental Conservation. "A lot of it is tar balls. The cleanup procedures are going to have to be tailored."Later Friday, Coast Guard Commandant Paul A. Yost Jr., President Bush's personal emissary at the spill, scheduled a news conference in Valdez to discuss Exxon's cleanup proposal.

Yost criticized the plan earlier this week as poorly drafted and lacking in specifics. The state also has criticized it and urged extensive changes.

Yost has the final authority to approve the cleanup plan.

After a wind- and rain-swept six-hour tour of the area late Thursday, Vice President Dan Quayle said he believes "Exxon's going to have to do more than they think they're going to have to do."

Quayle, returning from a 12-day Pacific tour, met with a group of Cordova residents before heading to the USS Juneau, a Navy ship used as a base of operations for part of the spill cleanup, and to Smith Island.

The tanker Exxon Valdez slammed into a reef in Prince William Sound on March 24, causing the nation's largest oil spill and sullying hundreds of miles of Alaska coastline.

Under Exxon's proposal, 364 miles of coastline will be cleansed by Sept. 15, although nearly 200 of those miles may be left to be scoured by wind and wave action.

In other developments Friday:

-The lawyer for Joseph Hazelwood said the fired tanker captain was not drunk when he left the vessel in command of his third mate prior to the shipwreck.

-The Alyeska Pipeline Service Co. in Valdez, which pipes oil to tankers from the trans-Alaska pipeline, said it will require that tankers leaving Valdez be escorted by special, 200-foot-long spill-recovery boats.