Is a decision by a federal court not reviewable because the court did not exercise its authority to depart?

Appellants contend the court's decision is reviewable because the court did not exercise its discretion but, rather, believed it lacked authority to depart. See, e.g., United States v. Martin, 938 F.2d 162 (9th Cir.1991), cert. denied, 112 S.Ct. 1679 (1992). To support their allegation, Appellants cite to the court's statement during sentencing, "I'm reluctant to see these young men with no prior criminal record incarcerated for the length of time the guidelines would seem to require, but I can't find any legal basis for a downward departure." (emphasis added).