The Sea Guard or Sea Guardian Helicopter was created to fill a need for a smaller amphibious helicopter.
The design began in 1957 for the S-62A (later designated HH-52A), using the rotor and transmission from the S-55 and a single turbo shaft and fuselage similar to the H-3 (S-61) Sea King. The first prototype flew in May of 1958.
The HH-52A was very similar in appearance to the H-3 Sea King, except for the new cabin windows and three blade rotor.
The Sea Guard utilized a starboard side rescue platform that folded down for on-the-water rescues. The Sea Guard was fully amphibious with the wheels retracting into the pontoons.
The US NAVY, acting for the US Coast Guard, procured a total of 99 HH-52A’s accepted under contract # TCG42044.
Other principal versions were the S-62C for export and S-62J, built under license in Japan.