"Blue Water" means different things to different sailors. The Newport 33 is a scaled up N30, a Gary Mull design from the early 70's. A fast, roomy and agile sailor for that era. I would classify it as a coastal racer/cruiser. I think of "Blue Water" in terms of design and build quality. The N33 is a coastal design. Any coastal design can do moderate "Blue Water" but the design is not ideal. Build quality is another issue. Build quality is tied closely to design however the builder can choose methods to save cost not just weight. The Newport was one of the better built production boats of their era but, for example. An N30 ended up on the rocks off the coast of California a couple of years ago and after getting beaten up and down for a while the keel was driven through the hull. Whether a full blue water boat would have survived the same conditions is questionable, but it would have likely lasted much longer before catastrophic failure.
Hopes that helps answer your question. The N33 is a nice boat for it's purpose.
BTW: I owned an N30 for 6 years and loved the boat.