Son of the Serpent
Pupil
Its the superior option because its far less likely to fail and lasts longer. Needs to be replaced less often. You lose it less easily (very easy to lose items in an aquatic environment realistically). Takes up less space. btw, you have to pass a check to use a potion while you are already submerged without just ruining the potion because you are under water. Furthermore it takes time in a round to activate a potion. Time you might not have. Furthermore if you are under really deep water you will be using magical means to protect yourself from that aspect of the environment most likely. Sometimes items arent on your person within this protective zone. Manybreasons you might need to leave items behind. Guess what? The potion bottle isnt gonna hold up. Even if it did the cork or cap would pop off long before the bottle shatters in most cases. Ruined. The spare ring not on your person will be just fine though. Even if you have to temporarily leave it behind for any of the multitude of potential reasons. Furthermore if already drowning a potion can be a problem. Dc check is not exactly a great one to take a potion while already drowning. Furthermore, good luck trying to get a person underwater whos already unconscious to take a potion of water breathing properly with water already filling their esophagus, airway, and oral cavity. Its difficult not to spill any underwater while conscious and drowning. Its way more difficult to pass the whole thing down someone's esophagus while already underwater with them already unconscious. Its going to just seep right out their mouth or nose if you arent really careful. Could be extra difficult in combat. I could continue the list of reasons the ring is the superior option in a heavily aquatic campaign for a whole page of this thread. Ive proven the point though. Ring>potion in this scenario.IDK where you learned math, but spending hundreds of thousands of gold to make two rings for each player is a smarter use of resources than casting 1 3rd level spell slot a day. They even have a druid for back up. It would cost them less to horde components to cast Raise Dead on the Wizard everyday. Not only that, but the spell can be ritually cast, so it doesn't even have to take a spell slot. The only time when you would need a magic item or potion is, when the GROUP has NO ONE who can cast that spell at all. They have 2 people who can cast it as a ritual and only need it cast once a day for the whole party.
Even if the party wanted to waste resources, it would be cheaper just to make scrolls.