Pinayev, I. Brutus, J.C.B. Gassner, D.M. Hulsart, R.L. Inacker, P. Litvinenko, V. Michnoff, R.J. Miller, T.A. Paniccia, M.C. Pekrul, W.E. Sorrell, Z. Tuozzolo, J.E. JACoW Publishing Geneva, Switzerland The Coherent electron Cooling (CeC) Proof of Principle Experiment at Brookhaven National Laboratory utilizes a 14 MeV CW electron accelerator and an FEL structure to demonstrate longitudinal cooling of gold ions circulating in the Relativistic Heavy Ion Collider. This unique combination requires proper selection of the diagnostics devices and their parameters. In this paper we present how we transformed design beam parameters into specifications for the instrumentation and hardware configuration. We also have developed tools enhancing diagnostics capabilities including solenoid beam-based alignment and in-line energy measurement. The achieved beam parameters as well as instrument performance are also shown.