The Sea Kings are older than the crews flying them.
In 1992 the Tory government of Brian Mulroney had put out a contract for EH101 (designated as CH149 Cormorant) to replace the Sea Kings. The Grits described the aircraft as "Cadillacs" and promised, in their famous 1993 campaign "Red Book" that they would cancel the contract. This was the only promise in the Red Book that the Grits kept. Canada paid half a billion dollars in cancellation penalties without a single aircraft to show for it.
It was not until 2004 that the Grits put out a new contract to replace the Sea Kings with a military version of the civilian Sikorski S-92. The new bird is designated as CH148 Cyclone. Sikorsky also was granted a contract to modify the chopper decks on the frigates. Sikorsky keeps postponing the delivery dates.
Canada currently CH149 Cormorants purchased in 1998 for SAR duties to replace the CH-113 Labrador. The Canadian Forces would have preferred to have the same aircraft for SAR and for the frigates (albeit with different configurations) but politics dictated otherwise.