It is indeed a Spud "pole" instead of putting Anchors or Chains out to keep Her in position they just put the Spud down to keep her her steady, the Dutch are very keen users of Spuds even on their Steel Motor Yachts although you don't have a Pole sticking out above the Deck as their Spuds are Telescopic, they also take into account the rise and fall of the Tide, Industrial Hydraulics or wonderful it's a pity the Oil stinks like Cat Urine.