You could probably throw in some sort of sea-dragon. I forget my dragonlore (I loved the <color> Dragon Codex books, and those had a nice listing on dragons being friendly, even if they were chromatic. I also read other ones too, but I remember those most. Shame they were canceled.), but I think there was some color that liked water.
I mean, if they have prehistoric dragons roaming around and suddenly revealing themselves, why not one that found the titanium fish nicely tangy?
There are several "Sea Dragons" though of the "Main Ten" it would be Bronze Dragons.
There also exist 1E Aquatic Dragons Lawful Evil wingless Dragon. Has a Breath Weapon that is a "cloud of chemicals" which deals Lightning Damage. Can't breathe Air only Water. Since this was Early DnD and Sorcerers were not a thing yet despite High Intelligence not many could learn Wizard Spells due to the difficulties of storing Spellbooks underwater, so they liked collecting Magic Items to use.
Like the other two "Wingless Dragons" the Sand and Rock Dragon introduced in the same Dragon Magazine Issue (#134) they never really "took off" while Ichtyodrakes, Astral Dragons, Were Dragons (later renamed Song Dragons in the Forgotten Realms) and Fang Dragons were featured in later stuff.
But it's Dragonlance that takes the cake for Sea Dwelling Dragons.
First up are Sea Dragons. Essentially True Dragon versions of Dragon Turtles they have longer limbs with webbing in between their claws, long snakelike necks and a tail nearly as long as their neck with a large fin at the back. Like Dragon Turtles they have a Steam based Breath Weapons.
When a Sea Dragon mates with a Chromatic you get an Amphi Dragon. Basically fully amphibious Giant Dragon Toads with wings they are incredibly ugly, and not only have a line of acid as a Breath Weapon, but are covered in warts that ooze Acid when popped.
Then we have the Brine Dragon, who are Black Dragons that have adapted to a fully Aquatic Lifestyle. They have lost their horns and their bodies now resemble a Plesiosaur, trading arms and legs for fins. As their name indicates they have a Salt/Alkaline Breath Weapon that burns like Acid rather then a line of Acid like most Black Dragons. Notably there is a more "pretty" looking Sub Species of Alkali Based Black Dragons native to Krynn as well, lacking the "Skull Face" so associated with more traditional Black Dragons.
Like the Chromatics who they are "related to" the above are all Evil.
But there is another Sea Based Dragon on Krynn more closely related to Metallics. The Aquatic Dragons (II) are basically Dragons combined with Seas Horses with much longer serpentine tails and a set of arms but no legs. The Males even carry the Eggs in a "pouch" after the female lays them. Their Breath Weapon is Unique in that it varies by the environment. Out of Water it is a cloud of chilling vapor, but In Water it is cone of cold strength sapping black ink.
................Yeah as much as I love Dragonlance it got really weird at times and it seems the Writers went out of their way to make all kinds of "Special Snowflakes.
Now there is also a third kind of Aquatic Dragon introduced in the Dangerous Denizens 3.5E Book that has a Sonic Based Breath Weapon.
Even with these three different versions it is nowhere near as bad as the confusion around the different versions of the Purple, Orange, Brown and Yellow Dragons.
For those who don't know the Purples have 3 since they have been merged with Deep Dragons (1st Version had Force/Energy Damage Breath Weapon, then Deep Dragons were changed from Acidic Vapor in most editions to Psychic Damage in 4th), the Yellow also has 3 ( 1st V Breath based on Cloud Kill and Cause Disease, 2nd V Line of Salt Crystals, and lastly Superheated Air and Sand) as does Brown (1st Version has two Breath Weapons, Faerie Fire or Lightning Bolt, 2nd V has Acid, 3rd V has Scouring Sand) and Orange only has two (1st V has a Cone of Color Spray Breath Weapon, Second a Sodium Based Slimy Mucus that explodes into Fucking Napalm).
So even in the Same Edition (1st and 2nd Versions of Yellow and Orange Dragons are both 1E) the "Extra Chromatics" are not agreed upon while at the least it seems the three Aquatic Dragons were different Editions (1E, 3E and 3.5E).
In short as to be expected there are a lot of Dragons in DnD, and when some get left to the wayside when they get brought back they might not even resemble the Original Version.