D&D Random Encounters for 5E - Underwater

Encounters might be a meeting with a patrol of guards at an old shrine or a familiar looking for aid. It might be an ambush in the wilderness, a stand-off in the city or a monster in the Underdark.
Encounters underwater bring visions of murky seas, vast reefs and dark depths. They might occur in a kelp bed, an underwater cave or by a long-forgotten shipwreck

level: terrain: sources: type:

At a narrow tunnel entrance (nearby is an undersea mountain)
They are curious about a nearby light source
In a fight they focus on the foe that stands out most
Possibly... during the fight a wall, tree or building starts to collapse or fall
Difficulty... 450 Deadly

At a mound of dead seaweed near a patch of dying sea mushrooms (there is the sound of nearby music)
They are hiding from a nearby threat
In a fight they attack whoever is nearest
Possibly... they have a Decanter of Endless Water
Difficulty... 600.0 Deadly

combatsahuagin

1 Sahuagin Priestess (Monster Manual p.264)

At a dangerous chasm (the area is associated with squids)
They are exploring a cave mouth
In a fight they focus on the foe that stands out most
Possibly... during the fight someone disturbs a swarm of bees
Difficulty... 450 Deadly

At an ancient coral-carved chambers (which is a portal to the elemental planes here)
They are bearing symbols of a deity of the sea
In a fight they attack anyone who looks like a source of food
Possibly... they have mason's tools
Difficulty... 700 Deadly

At a sunken temple to a power of strength (it is disguised by a hallucinatory terrain)
They are bearing symbols of a power of travel
In a fight they attack whoever is causing them the most pain
Difficulty... 600.0 Deadly