Sea Time Question in Upgrading to 500 ton master: oceans

Mariners, does anyone know if when attempting to upgrade from 150 ton to 500 ton master, the sea time recency can be waved if a refresher course is taken? Similar to, for example, a mariner does not have recency to maintain their license therefore they take a refresher course to fulfill said requirement. Thanks!

The recency requirement in 46 CFR 11.201© cannot be waived as the CFR does not provide for waivers or an alternative. In addition, the recency requirement specifically state that the service must be “on vessels”, so sea service credit from refresher courses or other approved training or from closely related service (46 CFR 11.211(b)) cannot be used.