Possible Clues:

• Horny beast hurried over with young King Henry
• Water initially flowed up - almost 50% whale appearing
• Marine creature managed to back onto itself almost
• Warn Hal there's a whale here
• This might warn Henry of a sea monster.
• Is that the hidden way to warn Henry there's a tusk there
• An Arctic whale
• Toothed whale from the Arctic
• Hurried up with most of a whale for a whale
• Whale of a way to have hurried back with most of the whale