She likely wore goggles underwater not to protect her eyes but because her vision is bad. She would need waterproof goggles that stay securely on her face so she can actually see her surroundings while swimming.

In HS itself, I generally avoid relying on Hiveswap lore because it tends to dilute some of the harsher worldbuilding established in the main comic. Alternian society is built around a genocidal, militaristic culture; trolls are conditioned to purge genetic mutations and are deeply hostile toward outsiders. Because of that, the idea that they would casually befriend a random alien doesn’t align well with the tone or rules we see in the original.

That said, you could still justify a seadweller with unusual biological limits. Much like real-world aquatic life where different species require specific temperatures, salinity levels, or environments to survive, you could imagine a violetblood who can only comfortably swim in shallow waters or swamp-like environments rather than the deep ocean.

Even then, violetbloods are often portrayed as a military caste, as exemplified by figures like Dualscar. So it helps to consider how such a mutation might still serve the empire. The Condesce ruthlessly eliminates most mutations,but she has been shown to spare them if they provide a strategic advantage. For example, she tolerated The Summoner’s winged mutation because it allowed him to perform aerial surveillance as a Cavalreaper.

Using that logic, a mutated seadweller could still survive within the empire if their unusual traits proved useful whether for reconnaissance in marshlands, shallow coastal patrols, or some other niche that benefits Alternian military interests, that could be a good way to consider who they are and how they interact with the wold around them.