...the Court, rather than to the parties. You will therefore have to, in some sense, "blame" the Court. I agree that it would not be an affront to the Court to say that other institutions may be preferable.
UNCLOS has established a mechanism by which the ICJ is only one of the available institutions, and the ECHR expressly excludes recourse to any court other than the ECtHR on questions under the Convention. It is, however, more than slightly unfair to describe the ICJ as 'cumbersome' and therefore inferior to the...