Let me preface this with saying I'm a cardiologist, not a hematologist.
You mention that you have Protein C deficiency but you are not on Coumadin so i suppose that means you discovered this genetic problem without having a thrombotic ("blood clot") event?
Protein C deficiency in and of itself is not a problem with diving. Should you need to be on coumadin there are theoretical issues of increased bleeding risks from barotrauma, injuries, and (possibly) should you suffer a neurologic DCS event. However, coumadin also is not a contraindication to diving.