Vorpostenboot (plural Vorpostenboote), also referred to as VP-Boats, flakships or outpost boats, were German patrol boats which served during both World Wars. They were used around coastal areas and in coastal operations, and were tasked with – among other things – coastal patrol, ship escort, and naval combat. Some Vorpostenboote (and submarine chasers) were given heavier AA guns and re-rated as Flakjaeger or Flakkorvetten, but the heaviest armed German AA batteries were converted old warships.