A Coast Guard cutter, a helicopter and a merchant vessel searched the Gulf of Mexico yesterday for 13 crewmen missing from the Panamanian freighter Ukola, which broke in half in heavy seas Wednesday and sank.

Only the captain and two crewmen have been found alive. Seven bodies were seen floating in the water, but the rough seas and 25-knot winds prevented recovery of the dead, a Coast Guard spokesman said.

Elswhere:

Bodies of five of the 46 sailors and Marines killed this week when a Navy launch collided with a Spanish freighter arrived early today at Dover, Del., to be placed in caskets before being escorted to relatives.

A Coast Guard proposal to bomb the remains of the wrecked tanker Argo Merchant off Massachusetts has drawn fire from fishermen and marine biologists who say it would disrupt the spawning cycle of several species of fish.

The Coast Guard said it has called off the search for three crewmen still missing since a Liberian-registered oil tanker broke in two Monday night in the pacific 200 miles southeast of Midway island. Meanwhile, the oil spill caused by the rupture of the tanker Irene has spread 70 miles in length and 60 miles wide in less than two days, the Coast Guard said.