Related Clues:

• Sea beast
• Sea creature (reported close behind by the 10 to the 9!)
• Member of dolphin family
• Mammal whose name derives from the Latin words for "pig" and "fish"
• Whale's kin
• Petty officer read Grace Leviathan perhaps
• Sociable swimmer ex­pressed sympathy for sick cat
• Mammal seen in river? Get up to catch its second appearance
• Swimmer's half-heartedly feeble balance
• Cetacean's mutating, I propose
• Warm-blooded swimmer's inferior balance giving nothing away
• Mammal meat — there's a kilo out on balance
• Type of dolphin
• Sea-creature I propose doctoring!
• Sea creature's elegance beneath river, right?