Cuba says the weapons are "obsolete." And experts who identified early Cold War relics such as the Soviet-designed SA-2 air defense system among the ship's cargo say that's not far from the truth.
"Today there is no reason for any Western pilot to be hit by an SA-2 -- if you get caught by one of them, you've done something bloody stupid, or you've got very bad luck," said James O'Halloran, editor of Jane's Land Based Air Defence and Jane's Strategic Weapon Systems. "No modern country wants to be seen with those."
But others saw the weapons haul as a more ominous sign.
In a letter to U.S. Secretary of State John Kerry, Sen. Marco Rubio of Florida, a frequent Cuban government critic, described the weapons shipment as a "flagrant violation of multiple United Nations Security Council Resolutions."
"I believe that this revelation, in addition to Cuba's failure to address its abysmal human rights record, should finally prompt the (Obama) administration to re-calibrate its misguided and naive Cuba policy," Rubio wrote. "The administration should immediately reverse its January 2011 decision easing restrictions on people-to-people travel and remittances sent to Cuba; as well as immediately halt granting visas to Cuban government officials."
Forbes.com columnist Gordon Chang told CNN's "Erin Burnett: OutFront" that the boat's cargo was a warning sign that North Korea could be supplying Cuba with weapons.
"This is a country which is just 90 miles away from American shores," he said. "Now, if they can smuggle missile radar into Cuba, you know, God knows what else they can put there. We do not need a replay of the Cuban missile crisis, this time with the North Koreans' fingers on the triggers instead of the Soviets."
The U.S. government's assessment is that Cuba might be trying to further its arms relationship with North Korea in the wake of Russia's not being interested in doing the upgrade work on the aging stockpile, a U.S. official said.