The operatic repertoire offers few musical depictions of the seashore as vivid as those in Wagner’s “Flying Dutchman” and Britten’s “Peter Grimes.” Sure, some operas (Britten’s “Billy Budd,” to name just one) venture right into the briny deep, but these two masterpieces remain balanced right at the juncture between land and water. The opening program by Symphony Silicon Valley, conducted by Paul Polivnick, includes those orchestral pictures without any of the vocal elements.