Two of those convicted over the sinking of the Tongan interisland ferry the Prince Ashika have raised no objections to queries over their sentences in the Court of Appeal.
The Ashika sank in August 2009 with the loss of 74 lives.
The ship's skipper, Maka Tuputupu, and his first mate, Semisi Pomale, were jailed for four and five years respectively, but with the first three and a half years suspended.
The Crown contends judge Robert Shuster couldn't suspend a sentence beyond a maximum of three years.
The Shipping Corporation of Polynesia, which operated the ferry, is appealing against the nearly 600,000 US dollar fine it was given.
Radio Tonga reports the Corporation's lawyer Vuna Fa'otusia as telling the Court of Appeal the company's in no position to pay.
But the acting Solicitor General, Sione Sisifa, says the Court needs to take into account that such a fine may deter other companies from making similar mistakes.
New Zealander John Jonesse, who headed the Corporation, is appealing against his conviction and his five-year jail term.