Possible Clues:

• Marine mammal and mammoth, perhaps close up
• It's a beastly sight seeing Helen and Pat drunk on exotic ales
• Large marine creature
• At half 11, ring round county for marine giant
• I wallow in the drink, pale ales, then go dizzy
• Mammal with a trunklike proboscis
• It has a snoutlike trunk
• I'd never forget to secure a large animal
• Marine animal, mammoth close up
• Great swimmer's way of stopping water getting into trunks?