Seaick Brothers

Seaick Brothers (シーイックブラザー, Shīikku Burazā): The Seaick Brothers are a trio of submarine style Headders that combine onto Gosei Great to form Seaick Gosei Great. They are composed of Manta Headder (マンタヘッダー, Manta Heddā), Sawshark Headder (ソーシャークヘッダー, Sōshāku Heddā), and Hammershark Headder (ハンマーシャークヘッダー, Hanmā Shāku Heddā)

Manta Headder
MantaHeader is a manta ray mecha that's a member of the Seaick Brothers. Forms the head of Seaick Gosei Great.

Hammershark Headder
Hammershark Headder is a hammerhead shark mecha that's a member of the Seaick Brothers. Forms the left hand of Seaick Gosei Great.

Sawshark Headder
Sawshark Headder is a saw shark mecha that's part of the Seaick Brothers. Forms the right hand of Seaick Gosei Great.

Seaick Gosei Great
After combining with the Seaick Brothers through the Seaick Armament (シーイック武装, Shīikku Busō), Gosei Great becomes Seaick Gosei Great (シーイックゴセイグレート, Shīikku Gosei Gurēto). Seaick Gosei Great can scan an opponent's weaknesses using the high sensitivity sonar Seaick Analyze (シーイックアナライズ, Shīikku Anaraizu) on its right eye. Seaick Gosei Great's final attack is the Seaick Strike (シーイックストライク, Shīikku Sutoraiku), a combination hammer-punch/downward slash move.

Another Seaick Gosei Great
When using the Manta and Hammer Headders as hands and the Sawshark Headder as chest armor, Gosei Great becomes Another Seaick Gosei Great (アナザーシーイックゴセイグレート, Anazā Shīikku Gosei Gurēto).

Additional Formations

 * The Seaick Brothers can unite with Landick Brothers, Skick Brothers, Gosei Great, and Datas Hyper to form Hyper Gosei Great, and further with Groundion and the Knight Brothers to become Ground Hyper Gosei Great.
 * The Hammershark and Sawshark Headders can unite with the Taka Headder, Landick Brothers, and Gosei Great to form Sky-Land-Sea Gosei Great.

Trivia

 * The Manta Header helmet resembles the hat of a pirate captain, with an eyepatch that acts as a scope to lock on to targets. This would serve retrospectively as a foreshadowing of the next Sentai after Goseiger.