Against who?
Three hundred fifty ships is not enough.
Well then how do you know we don't need seven hundred? Or eight hundred?
How do you know what we need. You are admittedly ignorant on the subject.
That you do not even know the capabilities of other navies is indicative of your ignorance.
When we had a policy that the U.S. Military was to be able to fight two major wars simultaneously essentially in Europe and Asia, analysis concluded a six hundred ship navy was the minimum needed to control the sea lanes and project American force. At the time the Soviet Union, North Korea, and China were considered likely adversaries. Today you could make the case for Russia, China, DPRK, and their allies as likely opponents. I would be happier with 750 ships personally.