Highly unlikely that any attempt to renegotiate new UNCLOS treaty would succeed
Myth: The United States could and should renegotiate a new law of the sea agreement, confined to the provisions on navigational freedoms.
Reality: Assuming, for the sake of argument, that this were a desirable outcome, other countries would have no reason or incentive to enter into such a negotiation. The Convention is widely accepted, having been joined by over 150 parties including all other major maritime powers and most other industrialized nations. Those parties are generally satisfied with the entirety of the treaty and would be unwilling to sacrifice other provisions of the Convention, such as benefits associated with exclusive economic zones and sovereign rights over the resources they contain, as well as continental shelves out to 200 nautical miles and in some cases far beyond. And parties that would like to impose 20 new constraints on our navigational freedoms certainly would not accept the 1982 version of those freedoms.