I think good for BAE and the US Navy.
Correction though, the US navy ditched at sea testing because of budget reasons, not because its "wasteful" or useless... Rail guns are being developed for at sea deployment - ie. shore bombardment and anti-air capability,
Both of which will be used at sea. At sea testing in real-world conditions is a MUST, not a luxury. The medium-voltage, direct-current transmission network replacing an alternating current based system must be tested in at-sea conditions. Risk assessments must be conducted in real-world testing. ie. AT SEA. If the US Navy is to ever deploy rail guns at sea, they too will eventually test their prototype at sea. Hyper-velocity rounds or no.
+ Who said land and at sea tests were conducted with a single prototype?