Abstract: An apparatus for mounting underwater marine detection equipment on a waterborne vessel is provided having a baseplate which is secured to a side of the waterborne vessel. The baseplate extends outward from the side of the waterborne vessel over the surface of the water. A shaft holder bracket is rotatably mounted to the baseplate such that the shaft holder bracket may rotate in a plane generallyparallel to the forward and reverse direction of the waterborne vessel from a first position to a second position. The shaft holder bracket has a through passageway to receive a shaft. An elongate shaft having an upper portion and a lower portion which are rotatably joined and separable, is slidably engaged through the passageway in the shaft holder bracket, such that the elongate shaft can rotate and slide within the shaft holder bracket. The shaft holder bracket has means to secure the elongate shaft from rotation and sliding.