From April 2018, the only aircraft you can fly with an NPPL SSEA are non-EASA types, so that excludes 4-seater Piper and Cessna aircraft, for instance. It MIGHT be possible that once we leave EASA on 1/1/2021 the CAA will grant permission to fly these types on an NPPL SSEA, but on the other hand, they might all be grounded as they might lose their Certificates of Airworthiness...
TOO