Iron slowly corrodes, especially in water so it has to be replaced before it all rusts to pieces and falls apart.
Steel ships began to be developed in the mid-19th century, with the first iron-hulled ships appearing around the 1830s. The transition to steel vessels occurred in the 1860s, with the launch of ships like the HMS Warrior in 1860, which was the first ironclad warship. By the late 19th century, steel had largely replaced iron in shipbuilding, leading to the construction of larger and more durable vessels.
Gravity causes the ships iron anchor to sink to the ocean.
Ironclads.
boats
Wooden ships were primarily replaced by iron and steel vessels in the late 19th century, which offered greater durability, strength, and operational efficiency. The introduction of steam power further accelerated this transition, allowing ships to travel faster and more reliably than their sail-powered predecessors. By the early 20th century, modern shipbuilding techniques and materials, including the use of welded steel, had largely supplanted wooden ships in commercial and military applications.
There are lots of ships named Iron Maiden about.
Ancient ships were made from wood with nails and iron fittings. Modern ships are steel.
Monitor and Merrimack (vessel ships). Only fought once. Made of iron at the front. Ironclad ships were a new invention. These ships were covered with iron plates that would deflect shells. Tin-clad ships were river boats that were lightly protected by iron. "Blockade Runners" were a name applied to a varitey of fast ocean ships that were used to get through the Union blockade.
Tudor ships were constructed of wood (planking, beams, masts and spars), iron nails and iron brackets, tar and unwoven rope to seal the gaps in the planking. Ships were constructed like this for centuries, until ships were finally constructed almost entirely of iron.
delivering iron
The USS Monitor.
B/c the ships were more armored with iron