July 24, 2026 — The US Environmental Protection Agency has exempted a specific new lobster boat model in Chatham, Massachusetts, from Tier 4 marine engine requirements, marking the first time the agency has invoked this exemption authority since the waiver process was established in 2024.
The exemption allows the Chatham vessel builder to use a Tier 3 engine after EPA determined that currently available Tier 4 engines cannot fit within the applicant’s vessel design while maintaining essential operational requirements. The exempt engine must meet Tier 3 emission standards and be labeled to prevent use on other vessels.