what creatures can I use for a random seafaring encounter?

[dehro]

party of 6 players, all level 3...
they're about to embark on a 3 day trip towards an island.. it starts in a fairly placid trait of sea..once they are in really open waters, it's fair game.

I don't want to kill them, just challenge them adequately without going off the deep end (yes, I went there), and land on uncanny valley kind of creatures... I am open to single or couple of big brutes, or maybe pirates with a flavour, or something more uncommon but not mind boggling. It's meant to be a straightforward "random encounter".

We're playing high/classic fantasy and I am fishing for suggestions.

[Amnestic]

"Fishing". Heh.

Kua-Toa or Sahuagin raiding party to grab slaves/food/sacrifices works as a pirate-alternative.
1-3 Sea Hags would work too depending on the size of the crew. Their death glare is scary since it forces your health to 0, but not immediately lethal if the hags don't go in for a killing blow, giving people time to stabilise/heal them back up.

[J-H]

Merfolk

Sahuagin

Giant sharks (MM pg. 328, 1800 XP each) swim alongside the ship for a while. They may bump it and rock it with their noses, but don’t have what it takes to overturn it.

Storm
A short, sharp squall overtakes the party, lasting 2d4 hours. The waves are choppy, and the boat requires removal of at least 2 gallons of water per minute to avoid being swamped. The storm is too disturbing for anyone to rest.

Chuul (1): MM creatures, drawn to magic items.

Dragon: A young dragon (water-breathing type) "collects a toll" in money, magic items, or blood. Can be solved through bribery, flattery, or force.

A floating shipwreck showing signs of having been partly crushed by something that wrapped around the ship. There are old, sun-weathered bloodstains on the deck. All the supplies are gone.

Kelp Sea
The water is full of waving seaweed, free-floating and growing all the way up to and along the surface. The seaweeds stick to the ship, and a Perception DC 15 check shows that they are “cleaning” the outside of it free of dirt and organic matter… and then working on the wood. The kelp does 10 acid damage per hour to the ship as the aggressive plants begin to digest the boat.
It takes two people working consistently to keep the kelp peeled away; magical solutions such as coating the outside of the air-skiff in ice will work, but may require renewal throughout the night.

Kuo-Toa (triton, merfolk, skum, tortle, whatever) minions of an aboleth seek one of their sailors, who made a "bargain" with the aboleth and is trying to get away. Said sailor may have minor warlock powers if it comes to battle.

[dehro]

"Fishing". Heh.


heh... unlike the other one, this was an accidental pun.

both of you, thanks for the ideas.. I have enough to work with.

[Catullus64]

Are they on their own boat with nobody else, or are they on a ship with its own crew?

If the latter, my preferred option would be sirens. Stat them like Merfolk, and have about a dozen of them lounging on a reef near where the ship passes. On any round, they can use their actions to sing a luring song. At the start of its turn, a creature that can hear the song must succeed on a Wisdom saving throw with a DC equal to 8 + the number of mermaids that sang this round, to a maximum DC of 15. A creature that fails the save is Charmed by the sirens for as long as the song lasts; while charmed, a creature must attempt to reach the sirens by whatever means are available. A creature can attempt another saving throw at the end of each of its turns, ending the effect on itself on a success. A creature that is already charmed but becomes unable to hear the song makes these saving throws with advantage. A creature that succeeds on a saving throw or ends the effect is immune to the siren song for 24 hours.

For the sake of the fight, the NPC sailors will always fail their saving throws. The sailors will attempt to steer the ship towards the sirens, wrecking it upon the reef if they are not stopped. Some will jump ship and swim towards the sirens, who will then take hold of them and drown them. The PCs (once they've all made their saves) will have to make some difficult decisions in the moment: attempt to fight and knock out the crew, attempt to swim/row out to the sirens and drive them off, fight the sirens from long range, or find a way to deafen themselves and the crew.

If the PCs are alone on their own boat, the encounter can still work, but requires some tweaking.

[DragonBaneDM]

Sharknado!

Made an encounter where a Giant shark and a bunch of other smaller specimens kept landing onto the deck and needed pushed overboard or reduced to zero HP while doing a "steer the ship" styled skill challenge to get out of harms way and effectively end the combat.

I used mine for an airship flying over water, but I think it'd work just as well on a sea-bound vessel!

[Bjarkmundur]

I'm always a fan of "oh you think it's a pirate ship, but instead of pirates boarding you it's a bunch of smugglers terrified of the Cockatrices that got loose on their ship"

[dehro]

all good ideas which I will file away for later use.
I went with a bunch of Sahuagin and a Sahuagin priestess... the encounter ended up being not too challenging for them, even though it started in a rather funny way.

I had the captain of the ship identify a raft with a dead body on it for the bait it was and start to peel away, only to have the face of the party jump into the water to try and reach the person on the raft..which is when I had them roll for initiative.
As he was swan diving into the water, he flew past a few Sahuagin clinging to the hull as they were on the way up.. so he found himself out of commission for several rounds as he was climbing back aboard (I was generous in allowing that in the first place, since he never bothered to check if the ship had even slowed down... I would have been within my rights to have the ship, now under attack, float several hundreds meters away, leaving him stranded on the raft with a dead body.. and out of the fight entirely.