Erik and his team had been sailing for two weeks since leaving the island base. The journey had been relatively uneventful so far. That didn't mean they fought no thaids, but they were weak.
The Chimaeric Demons took care of them, but Erik could see now why they said they were weaker than flying thaids. They were not weaker in terms of strength, but they could be fought easily compared to them.
The ship's systems were able to find them under water, and with the new brain-crystal-powered weapons, it was possible to kill them. In the past, Hin's fleet must have had many ranged users, and since the sea thaids attacked the ships, it wasn't hard for them to hit.
Flying thaids, instead, stayed in the sky, which was much harder to reach them.
Fighting sea thaids should have been easier if the ship was in a fleet. Thaids could avoid a single ship's attacks, but not if a fleet rained down attacks on them. It was impossible.