Armed with at 57mm. gun! Those were obsolete before WW2 ended, unless you were shooting at wooden buildings.
Perhaps it is a type and it will have a 5inch (125mm) gun or maybe a 75mm (3 inch) of which the Italians had a good model.
But doesn't seem like much aramament unless you are going to be taking on the local Sea Scouts in their rowboats.
It is not a typo. Modern 57mm guns with enhanced munitions are a far cry better than their WW II predesessors both in terms of range in in terms of the damage they inflict. Neither of these ships is suited or planned to be major surface combatants on the high seas. The LCS works close int to shore in knife cutting range, and the Coast Guard cutter is for maritime patrol and interdiction out to sea along our coasts.
"... doesn't seem like much aramament ...."
I wouldn't be surprised if they're someday retro-fitted with the new rail guns which are now under development. If I remember correctly, they're expected to start putting them in the fleet within about ten years.
Also note the gun being delivered by BAE:
MINNEAPOLIS -- BAE Systems has been awarded a contract from Northrop Grumman Ship Systems (NGSS) to deliver a second 57-mm Mk 110 Naval Gun system for its integration onto the U.S. Coast Guard's Maritime Security Cutter, Large. The gun system was selected as the main battery on the Large, a new ship under development as part of the Integrated Deepwater System program.200 rounds/minute of 57 mm is enough to ruin most people's day"The Mk 110 fires 220 rounds per minute with superior accuracy and has a range of up to nine miles," said Jeff Graslewicz, BAE Systems' Mk 110 program manager. "The Mk 110 is unmatched, and it's the perfect choice for the Maritime Security Cutter, Large - it's going to provide our sailors with sophisticated firepower, precision and protection."
The BAE Systems 57-mm Mk 110 Naval Gun system was also selected as the Close-in Gun System on the U.S. Navy's DD(X) ship. Additionally, Lockheed Martin selected the Mk 110 for its Littoral Combat Ship (LCS) Flight 0, and General Dynamics has baselined the gun system for its version of the LCS. Once in full-rate production the 57-mm Mk 110 will be manufactured at BAE Systems' facility in Louisville, Ky.
Or if you're shooting at small craft. The LCS is intended for inshore work, where we wouldn't be willing to risk a billion-dollar-plus Aegis cruiser/destroyer.
I'm confident that we're not talking about your father's 57 mm gun here. I bet the thing fires high at volume and high velocity.