You will purchase all necessary uniforms during your first week of training at OCS.  If you do not already own uniforms, please do not purchase them prior to arrival.  Uniform items are very specific, and purchasing them from any source other the an authorized Navy Uniform Store may result in you having to repurchase items and unnecessary expenditures. 
For prior service military, if you already own uniforms on the attached list, you will need to bring them.  This will alleviate you from having to repurchase them. 

Below is a link of all necessary uniform items along with cost.

Click here to open or download uniform requirements list