On Tuesday evening, August 7, twenty-four hours before the College of Lawyers' declaration was released, the conspirators in the naval high command had decided to start moving on an idea conceived by Vice-Admiral José Toribio Merino. This was to present the coup they were preparing as a "response" to a phony "Red coup." Naval intelligence had found out about a meeting to which roughly two hundred junior officers and sailors in Talcahuano had invited the Socialist party secretary Carlos Altamirano. The purpose of the meeting was to let him know that since June, the commanders of the Navy's warships had been haranguing their crews at sea, telling them that "we have to get that Marxist President Salvador Allende out of La Moneda," and "we Navy men have the patriotic duty to overthrow the present government." Altamirano, along with Miguel Henríquez, secretary general of the MIR, and Oscar Garretón, from MAPU, explained the Chilean political situation to the junior officers and sailors, emphasizing the threat represented by fascist officers, who were serving the North American multinational companies, and the national oligarchs. They emphasized the necessity of letting all the sailors know that "they should not obey fascist officers" should they give orders for an uprising against the government. (Details of this meeting were published in August 1973 issues of Chile Hoy.)
Toribio Merino and his intelligence advisers decided that this constituted sufficient evidence of a "Red coup" in the Navy. On August 7 they officially announced that "subversion" had been uncovered on the ships Almirante Latorre and Blanco Encalada, and the ringleaders were Altamirano, Henríquez, and Garretón. They announced the arrest of about fifty sailors and junior officers, headed by a petty officer named Cárdenas.
In the days following, reporters from left-wing newspapers managed to find out how, at the Talcahuano and Valparaíso naval bases, these sailors had been forced to sign absurd confessions after being brutally tortured. In the Valparaíso Naval Hospital they found a sailor whose testicles had been smashed. Wives and relatives of arrested sailors gave out to the newspapers the names of naval inteilligence captains in charge of the tortures.21 There were three basic types of tortures:
1. An open oil drum filled with urine and excrement was employed to submerge the head of the man being interrogated, to the point asphyxiation, every time he refused to answer or to confess to any crime he was accused of.
2. The prisoners were hung naked, head downward, from a gymnastics bar and struck repeatedly on the scrotum and at the root of testicles.
3. The prisoners were forced to drag themselves naked through "pool" full of hammer-broken rocks over which was hung, at about a height of one foot, a strong steel net to keep them from standing. They were made to crawl between the net and the rocks several times during the interrogations.