From the Octonauts Wiki, here are the Cetaceans creatures with their Size Comparison!

Table of Contents:

Rank	Characters	Size	Weight	Color
1	Blue Whale	105 ft	200 tons	Pale Blue
2	Bowhead Whale	60 ft	100 tons	Dark Blue
3	Albino Humpback Whale	60 ft	36 tons	Pale White
4	Scared Simon	59 ft	45 tons	Dark Blue
5	Mitch	52 ft	40 tons	Dark Blue
6	Gray Whale	50 ft	40 tons	Dark Blue
7	Omura’s Whale	39 ft	19 tons	Gray, White
8	Orca Whale	32 ft	6 tons	Black, White
9	Boris	20 ft	1.5 tons	Light Green
10	Beluga Whale	20 ft	1.5 tons	Light Blue, White
11	Berta	8 ft	0.158 tons	Pink
12	Spinner Dolphin	7 ft	0.077 tons	Silver
13	Hourglass Dolphin	6 ft	0.119 tons	Black, White
14	Baby Dolphin	4 ft	0.019 tons	Silver

We are activating the creature report! To see the animals in need of help, knowing a bit of their background will help rescue them! With Captain Barnacles, these characters seen in the show are weighed and sized.

What is a Cetacean?

From the ocean’s depths, they are a part of mammals that are in the aquatic group. In the Octonauts’ show, only the dolphins and whales are categorized under this order. They can breathe underwater, but they come up for a short while to the surface. Because of this, we see videos and captures of them swimming with tourists or locals. It’s as if they’re waving hello!

Biggest to Smallest

There’s no mistaking it for Blue Whale to take the 1st place with its enormous 105 ft. No one reached 100 ft other than this mammal. For the 2nd place, it started with 60 ft and ended at 20 ft for the whales. While for the dolphins, the biggest is Berta with 8 ft and Baby Dolphin taking the last place with 4 ft.

Heaviest to Lightest

Taking the top rank of this comparison, the Blue Whale stands in 1st place with 200 tons. No one else had a close size with the Blue Whale; there was a considerable gap from the 2nd place of having 100 tons. Landing in the 7th spot, Omura’s Whale shows up with 19 tons. While for the last place, Baby Dolphin still has some room for growth for its 0.019 tons.