Longer Vessels Now Allowed to Use Expanded Panama Canal Longer and deeper ships will now be able to use the expanded Panama Canal. After almost five years since the inauguration fo the Neopanamax locks, the Panama Canal Authority has announced increasing the maximum allowable length for vessels to more than 370 meters long, an increase of over 4 meters compared to the previous limit. The authority’s Advisory to Shipping No. A-23-2021 informs customers that, effective immediately, the maximum length overall for commercial and non-commercial vessels accepted for regular transits for the longer and wider locks is now 370.33 meters (1,215 feet), up from the previously established maximum vessel length of 366 meters (about 1,200 feet).