The Endless Sea (also known as the Endless Ocean) is the sea that surrounds every island and landmass in Ninjago.
Upon waking up, the Ninja and Wu do some stretches while sailing the Endless Sea. When he realized they weren't paying attention, they have to train until they can solve his riddle. When there's trouble at Darkley's, they left the Sea.
Two hundred years ago, Captain Soto's crew sailed on the Destiny's Bounty looking for the Dark Island. When No-Eyes Pete crashed into Ninjago's shores, the ship sank, killing its inhabitants.
In the present, Garmadon's crew flew above the Sea to chase after the Ultra Dragon. When Garmadon summoned the pirates, they flew away from the Sea to Ninjago City.
Lord Garmadon and the four remaining Serpentine generals fly over the Endless Ocean to try to find the Dark Island. After searching all day, Skales pushes Garmadon into the ocean so he can become the new Serpentine leader.
The Ninja used their their Elemental Powers next to the Endless Sea's shore. Later, the Ninja fell down the cliff, splashing in the Sea.
The Stone Army reached the coast in order to fire Dark Matter in Ninjago.
With no way off the island, Kai suggests they swim, but backed out after the water reached his chest.
The Elemental Masters flew over the Sea to reach Ninjago Island.
In a dream, Kai tells Lloyd he'll take care of him right before a Fangfish jumped out of the ocean.
Lloyd commanded the Ninja take out Stiix's support beams to drop the Preeminent into the Sea. When the Ghost Warriors supported her by surrounding her with houses, the Preeminent chased everyone to Hallows Trenches, destroying her.
- The Endless Sea was what truly defeated the antagonists of the fourth and fifth seasons of Ninjago: the Anacondrai Cultists and the Ghost Warriors.
- The Cultists were drowned.
- The Ghost Warriors were dissolved.
- Deepstone is found and mined at the bottom of the ocean.