A submarine is a watercraft capable of independent operation underwater.
On 17th March every year, the United Kingdom celebrates Submarine Day. On this day in 1898, the Irish engineer John Philip Holland, first successfully demonstrated his submarine called the Holland VI. The first successful submerged run happened on St. Patrick's Day(17th March).
His submarine used internal combustion engines on the surface and electric battery power while submerged.
Today, Submarines have one of the widest ranges of types and capabilities of any vessel. They range from small autonomous one or two-person vessels that operate for a few hours, to vessels that can remain submerged for six months.
The above stamp was issued by India Post to commemorate the President's Fleet Review in 2011.
Indian Navy celebrates its Submarine Day annually on December 8. The first indigenously manufactured submarine, INS Kalvari, was commissioned on this day in 1967.