Following Rumors and Spoilers from Toku Insider. Please don't take these rumors super "Cereal."
Also known as Kotaro/Kamen Rider New Den-O, has been rumored to be GoukaiRed.
The colors for the rangers are still unknown (Henshin Grid has a new poll now hat colors YOU would prefer), but most rumors point to the standard sentai color scheme (red, blue, yellow, green, pink).
The Gokaiger's transformation item is rumored to be called the "Ocean Phone".
Recent rumors state that the Gokaiger's main robot, the aforementioned Pirate Ship, is in fact to be based on Noah's Ark. If the Gokaiger utilize a vast system of auxilary mecha (rumored to be animals) then this Ark can store the mecha inside of it. The robot is supposed to be bulky, resembling GoseiGround. The Gokaiger's mecha are rumored to be called the "Goukai Sea Beasts", each mecha having the motif of a Sea Creature. The new Ranger Strike set features a new "Mothership" factor.
[The following rumored sea animals I decided to match up with others in popular culture. I have been dreaming for all sea animal mecha for years.]
GoukaiRed's Sea Beast is Goukai Whale.(Walilord from Pokemon)
GoukaiBlue's Sea Beast is Goukai Seiuchi (Walrus)
(Walrein from Pokemon)
GoukaiGreen's Sea Beast is Goukai Squid
(Squid Princess Hello Kitty)
GoukaiYellow's Sea Beast is Goukai Rakko (Sea Otter)
(Sea Otter Hello Kitty)
GoukaiPink's Sea Beast is Goukai Kurione (Clione/Sea Angel)
(Clione Hello Kitty)
In one forum topic, someone said there wasn't enough sea animals, that all the sea animals were done in sentai. Here are sea animals that have not been done as mecha:
Big White Shark
Stingray (there has been mantaray and horshoe crab)
Octopus (there has only been squid)
Orca (real one and not like in Go-onger)
And Sentai always repeat so I am sure they will fill it in with shark, whale, dolphin, lobster, turtle, etc.