Home Depot has metric stuff in the drawers in fastener area. Use a piece of paper and press hard to the screw hole to get diameter. Go and get the size screw, course and fine. I would be willing to bet it is a course thread. If it is big enough it may be a bolt. Mine is the style used for bicycle cables. I buy extras and they go in my ski expedition tool box. Nuts, bolts,washers and screws might get you or someone back on the water.