You could also link these potions to the order of souls. Maybe make it the grade 5 emissary mission and have to collect ingredients to get the potion.

Some other ideas:
Storm-caller potion - sends a storm over you for a set period (in addition to the regular storm, as I get this crosses servers, so wouldn’t be easy to just shift)
Fog-caller potion - raises a fog around you and your ship for 2 square miles in each direction

Ashen winds maelstrom - hails down an eruption of lava rocks and geysers around you (much like the ashen winds lords, but you are vulnerable to attack for a set period..

I like it! But also make it so you have a carry limit of only one or two potions in your inventory and - similar to curse balls - you cannot put them in any crates or barrels (so these cannot be stockpiled, you have to be selective/strategic, and campers can’t be camping).

How about potions that mimic the effects of ancient maws:
Barnacles potion - gives you a (time limited) coat of armour, making swords useless and needing to crack before you lose health

Feared redmaw potion - starts a timer where you explode and give fire damage your surroundings, but you are immune..

Some other ideas:
Mermaid's curse potion - locks you in a shell, so you can’t move, but can heal/buy some time. And if pirates get too close, they take damage.

Eel-ectric ocean crawler potion: gives you a temporary electric field armour that causes enemy’s to stun when you are hit (except throwing knife’s, for some reason..)

Megalodon potion: spawns a megalodon close to your ship that aggros the next closest ship

There should potions that u can drink to give u temporary effects and some can give u boosts such as.

We have a fruit that removes the mermaid for some time.

Shadow Potion: Temporarily turns u into a shadow, as a shadow u can not do anything or use weapons however u will be completely immune to damage

I see exploits...and trolls.

Healing Potion: gives u a bit of health back, self explanatory.

We have Meat....

Retreat Potion: Teleports u back to ur boat, but u can not take treasure with u obviously.

xD

Water Breathing potion: pretty self explanatory to be honest, when u drink it u will temporarily have water breathing

It's exploitable and annoying to see players underwater, attacking you from below the surface.

revive potion: when u drink it next time u get downed u immediately get back up

Yeaaah...

U can find all these potions randomly in barrels or crates.

With amount of stuff that already spawns and clutters our barrels.

@xorzius i got more

Reinforcement Potion: when u drink it, pirate legend phantoms/ghosts will spawn and aid u, the maximum amount will be 3, but i think it should be an uncommon potion to find since if a whole crew used this potion at once u would have 12 phantoms to defeat, either that or give it a timer, or both or make it so one person can use it and when the phantoms die u can use it again.

Water Breathing potion: pretty self explanatory to be honest, when u drink it u will temporarily have water breathing, so u can use it right when u are about to drown, and it can last for 1 or 2 minutes.

Flame Protection potion: protects u from fire damage, useful for repairing ur boat if its on fire and it can last 1 or 2 minutes.

(I know u may disagree on this one) revive potion: when u drink it next time u get downed u immediately get back up without anyone reviving u, obviously 1 use.

U can find all these potions randomly in barrels or crates. (My original idea was to have a potion brewer at every outposts but since some of the potions could be op I think its best we let pirates find them instead).