The thickness of the ozone layerâthat is, the total amount of ozone in a column overheadâvaries by a large factor worldwide, being in general smaller near the equator and larger towards the poles. It also varies with season, being in general thicker during the spring and thinner during the autumn.
Report Abuse. How ever many you have-is your fleet of ships. The US Merchant Marines currently have 465 ships in their fleet. The US Navy has a fleet of 286 ships. A fleet is the total number of ships. It can be the total number of a nation, or can be a fleet of ships operating under the same ownership.
USS Constitution under sail for the first time in 116 years on 21 July 1997. The United States Navy has approximately 430 ships in both active service and the reserve fleet, with approximately 70 more in either the planning stages or under construction, according to the Naval Vessel Register and published reports.