This bill establishes a new process for the temporary waiver of coastwise endorsement requirements for vessels. It mandates that the head of an agency must grant a waiver if a requesting party can reasonably demonstrate that no compliant product carrier is available to transport a specified good and that a good faith effort was made to locate such a carrier. These waivers are intended to address situations where domestic shipping capacity is insufficient for certain products. Any waiver issued under this process will be limited in duration , expiring by a specified date at least 30 days after issuance, with provisions for extensions if circumstances remain unchanged. Agencies are required to approve or deny waiver requests within 60 days; failure to respond within this timeframe results in the request being deemed granted for a 30-day period. Furthermore, the bill mandates that Congress be notified within 48 hours of both receiving a waiver request and issuing a waiver, with detailed explanations provided for issued waivers.