The Akvosians would be willing to help, if only to explore more of this world. However, the natives of Lake Dona will strenuously tell them that great power lives there, and they should avoid it.

That being said, you can probably get one or two of the more adventurous merpeople to tag along, and assist! One is a former warrior of Akvos, a merwoman with features that appear to be those of a lion fish. Another is a merman -- a former warrior of Polankos, who appears to be a tiger-shark. Both are capable, neither of them get along with each other, but each seem willing to set aside their differences to assist the Circle in exploration.