Green turtles are the biggest local turtle and can grow up to half a ton..and reach two meters long

World's oldest animal turns 175 "Harriet" a Galapgos Turtle was picked up by Charles Darwin and brought to England. She has spent the past 160 years in Australia, her current home is Steve Irwin's Australia Zoo, in the Gold Coast.
The giant clam can grow to 1.2m across and 230KG

Mantarays can grow to 7.5m across thats 25ft  Whitsundays mantas are usually not larger than 5m

Penguins "fly" underwater at up to 50k per hour.
Blue fin Tuna is the worlds fastest fish the can weigh up to 1.5 ton and swim at speeds over100 k per hour

Dolphins can hold their breath for 30minutes
Turtles hold their breath for 60 minutes or more.
Whales can to stay submerged for up to 2hours.
Fish just breath the oxygen that is in the water..

Humpback Whales
Can eat 6tons of Krill a day . They live to around 60 years of age and grow to 45 ton. They can propel this full weight out of the water with just 2 flicks of the tail.

Blue whale babies 4000 pounds at birth
They are the the largest known animal ever to have lived on sea or land.it can grow to over 100 feet long and weigh  200 tons. The blue whale's blood vessels are so broad that a full-grown trout could swim through them,
The blue whales heart is the size of a small car.

When Blue Whale calls for mating, it can be heard by other whales 1,000 kilometers away at180 decibels.