The Duke of Edinburgh's association with the Royal Navy and love of the sea will be a focus of the ceremony.
But no sermon will be delivered, in line with his wishes.
More than 730 members of the armed forces are taking part in the event, but there is a limit of 30 mourners at St George's Chapel, under Covid rules.
The ceremonial royal funeral will be broadcast on BBC One, with coverage beginning at 12:30 BST. The service itself will start after a national minute's silence at 15:00.
Prince Philip died at Windsor Castle on Friday 9 April, aged 99.
