Instead of a pirate attack, in order to get a combat encounter while travelling on a ship in a generic D&D world...

Instead of a pirate attack, in order to get a combat encounter while travelling on a ship in a generic D&D world, one should replace pirates with _____________.

Sexy pirates

Sea Monsters

Kraken pirates

Vikings, duh.

Shark people.

A patch of black puddings, bubbling up from the abyssal depths.

A skirmish with a dragon.

Those are a few I've used recently.

A very large and aggressive Sperm Whale.

A mutiny

Kuo Toa's are cool because you can have them revere the players if they do fancy shit

Sexy elf pirates.

>A patch of black puddings, bubbling up from the abyssal depths.
Holy shit this is genious.

They were encountered at night, started eating through the hull. PCs had to fight them in the darkened, rapidly-flooding hold in order to get to the breach and seal it. Fun, tense fight, with lots of PC panic as they tried to figure out what the hell was happening and how to survive.

A group of selkies, who have their most charismatic representatives distract the party while their companions break into the ship from below and start looting.

Winged great white sharks.

Dragonsharks

Squid pirates

Kappas riding dolphins

The spirit of their own ship deciding to fuck their shit up

A living storm

A sea serpent (bonus points for being a classic)

A mermaid civl war. Half of them are half fish people, the other half look ike harpies and constantly bitch and moan about how they were the firstborn. They want the ship's resources to fuel their war efforts and the crew to fuel their stomachs

Ghost jellyfish

Rust Monter: Portuguese Man-O-War Edition

Deep-sea fire ants building their nest in an underwater volcano that's coincidentaly just under the ship's path

Awakened Blue-ringed octopus horde.

very strong winds.
when they tack against them, the winds suddenly calm.
actually a pouty young wind elemental tantruming over not being able to push the party's ship where it wanted

...

Mermaid brigands.

They wouldn't be pirates unless the piloted a ship full of seawater onto the land.

I thpight he was looking for an encounter, not a TPK campaign

How does the gun work?

A magic whirlpool that takes you to an interesting setting, as opposed to the generic fantasy Tolkienesque shit that is most DnD settings.