Spek anchor is one type of stockless anchors. Spek anchor is modified from the Hall anchor, whose core of anchor head is located in the center of the pin center line to the bottom. The structure of Spek anchor is characterized that there is anchor crown plate and reinforcing ribs at the anchor crown. Therefore, the anchor claw is easily to turn to the ground and has better stability. Moreover, when collecting the anchor, its flukes keep naturally upward and overturn immediately when touching the hull plate to avoid damaging the shell plating.