First rate was the designation used by the Royal Navy for its largest ships of the line.The size and establishment of guns and men changed during the 250 years that the rating system held sway. From the early years of the 18th century, the first rates comprised those ships mounting 80 guns or more on three gundecks.By end of the 18th century, a first rate could carry more than 800 crew and displaced in excess of 2,000 long tons (2,000 t).hus over the 250 years (approximately) that the rating system of the Royal Navy was used, only a relatively small number of these ships saw service. Only one first rate has survived to the present. HMS Victory, Admiral Nelson's flagship at the Battle of Trafalgar, is preserved at HMNB Portsmouth and is in commission.