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.
For example, the goal of 306 ships stated in the Navyâs most recent 30-year plan included an objective for 52 small multi-role surface combatants, despite the Navyâs recently issued guidance that it is reducing its fleet purchase to 32 Littoral Combat Ship (LCS) hulls. 24 To make up the gap, the 30-year plan assumes that the Navy will procure another type of small surface combatant following the LCS program, but there is as yet no such program.