Pol III was a patrol boat of the Royal Norwegian Navy, used for guarding the inlet of the Oslofjord in early April 1940.

After firing a warning shot, Pol III closed with the German torpedo boat Albatros.

Leif Welding-Olsen, weakened by blood loss, did not manage to enter the lifeboat and drowned, becoming the first Norwegian fatality in open war between Norway and Nazi Germany.

Kampfgruppe 5 was temporarily turned back by Oscarsborg Fortress a few hours later, with the loss of the heavy cruiser Blücher.

On 1 October 2011, she was sailed on own power to Fosen Gjenvinning breaker's yard at Revsnes in Sør-Trøndelag for scrapping.