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THE DECISION TO SORTIE OR REMAIN IN PORT

General

Under normal circumstances, the decision on whether to sortie or remain in port is largely based on the answer to a single question: Would the vessel in question be better off attempting an evasion at sea or remaining in port?

Evasion rationale should include consideration of the following general factors:

• Vessel characteristics
• Berth and anchorage conditions
• Most recent tropical cyclone warning advisory
• Tropical cyclone climatology
• Individual vessel characteristics and berth/anchorage conditions are best determined by those responsible for each vessel and local port authorities.

Tropical cyclone warnings are issued by the Naval Pacific Meteorology and Oceanography Center/Joint Typhoon Warning Center Pearl Harbor for Department of Defense assets and are rebroadcast over the weather channel in Mexico. The interpretation of tropical cyclone climatology is addressed in the following sections.

Evasion at Sea

Evasion at sea is the recommended course of action for ships at anchorages or berths in La Paz and Pichilingue.

Commanding officers and ship masters with access to tropical cyclone warnings and advisories coupled with OTSR services are most capable of making the safest and most prudent decision for successful storm evasion and avoidance. In all sortie situations, OTSR services from Naval Pacific Meteorology and Oceanography Center (NPMOC), San Diego should be requested and utilized. The best sortie route in a specific tropical cyclone scenario is largely dependent on the location of the tropical cyclone and the forecast track. During any tropical cyclone threat there is normally one to three options available to the commanding officer and ship master. Selection of the best option is the objective of all concerned!

Keeping in mind that tropical cyclones normally approach the Port of La Paz/Pichilingue from the southeast, the following guideline is offered: An evasion route heading north within the Gulf of California and into colder water is the recommended course of action. An evasion to the south through the Gulf of California around the southern point of the Baja Peninsula and then west-northwest would eventually provide following wind and sea for almost all approaching tropical cyclones once the T is crossed. However, 48 % of all storms originate normally within 72 hours of CPA south of the Port, which may allow very little time and margin of safety to depart from the Port, head towards an approaching storm, cross the T, and maneuver in the open ocean to evade the north or north northwesterly heading tropical cyclones. In the event that a vessel cannot transit up the Gulf of California with an approaching hurricane, it is recommended that the ship proceed to an area west of Isla Del Espiritu Santo at about 24°20.8'N 110°20.7'W (Figure IV-12) and resist the effects of the hurricane underway in the lee of the island.

In all cases, the timing of the evasion is affected by: 

• The time required to make preparations to get underway
• The time required to reach open water and gain sea room
• The forward speed of the tropical cyclone
• The radius of hazardous winds and seas that can adversely impact a vessel's ability to reach open water.

Remaining in Port

Remaining in port is not the recommended course of action for all ships at the primary piers or anchorages in the Ports of La Paz/Pichilingue. The Commercial Pier in Pichilingue is considered to be the safest location if a ship cannot get underway. In that situation, two anchors and extra storm lines are recommended. The Commercial Pier in Pichilingue is considered a marginal haven for winds not exceeding 80 kt but it is still not considered to be a safe haven by the local Port Authorities.

Source: http://www.nrlmry.navy.mil/port_studies/thh-nc/mexico/lapazpic/text/sect8.htm