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Prince William got back into the royal swing of things today with a little "heir of the dog" at his first official event since his tour down under with his wife, Kate Middleton. The Duke of Cambridge downed a shot of rum, a submarine tradition, at the event to celebrate the $10 million restoration and re-dedication of the HMS Alliance, a World War II submarine, in Hampshire.

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As he took the swig of rum, William joked, "Where's everyone else's rum?" After viewing the submarine interior and living quarters, William was presented with a dolphin insignia, making him an honorary submariner. When a 66-year-old veteran invited Prince George back for a future visit, William told him that he was "lucky" the little one wasn't there.

"You're lucky he's not here," William said. "I think he' d get up to all sorts of mischief pulling on things."

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It's a busy week for His Royal Highness. Wednesday night, William follows in his mother's footsteps, hosting a charity benefit at Windsor Castle for the Royal Marsden Cancer Hospital. Prince William became president of the hospital in 2007, a post his mother Princess Diana also held. The charity was a favorite of Diana's - a portrait of her hangs today at the hospital - and he has said he's anxious to raise the hospital's philanthropic profile.

The star-studded guest list for Wednesday's charity benefit includes designer Ralph Lauren, who has been a generous donor to breast cancer awareness, and Princess Diana's favorite photographer, Mario Testino.

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