Annex I: when a navy may replace a warship

Annex I turns replacement into a calendar. Surface vessels over 3,000 and up to 10,000 tons became over age after 16 years for pre-1920 keels and 20 years for later ones; the corresponding limits for smaller vessels were 12 and 16 years around a 1921 cutoff. Submarines became over age after 13 years. Replacement keels could be laid three years before eligibility, reduced to two years for vessels of 3,000 tons or less. Delay did not cancel a navy's replacement right, but an over-limit predecessor had to be disposed of when its successor was completed or acquired. Loss or accidental destruction allowed immediate replacement.