The drilling capability of abrasive water suspension jets (AWSJs) under submerged condition decreases steeply with the increase of the standoff distance, and effective working distance for drilling and cutting is restricted in small standoff distance region. When the standoff distance is small, the nozzle may be damaged by the reflected jet. In narrow environments the nozzle can not be set closer to the work sometimes. Accordingly we have to find methods to extend the effective working distance for submerged AWSJs. In this paper, a sheathed AWSJ nozzle is proposed as a means extending the effective working distance for submerged AWSJs. Experiments are conducted to clarify the drilling capability of the sheathed AWSJ nozzle with specimens of stainless steel. Observation of the jet is also carried out with and without abrasive. A sheathed nozzle is useful for extending the effective working distance between the nozzle and works without drastic reduction in drilling capability.