Private Peter Perkins wants to change his branch of military service. He is currently in the army, but wants to join the navy. To leave the army, he must get out of his tank. He then has to go on board a ship to join the navy. Change ARMY to NAVY by changing one letter at a time. The change must go through TANK and SHIP. Each change must produce a valid word in the English language. No word can be used more than once.
ARMY ---- TANK ---- SHIP ---- NAVY
Today's brain teaser courtesy of Braingle.com.