Pelikan, it's versatile as a color but more a spring/summer texture and fabric than a four-season. The D'Avenza and Partenopea offerings are great additions to a strong wardrobe, but the pickings for standard navy jackets are pretty slim. I'd put some time and money into a navy jacket that is well-made, versatile, and fits you--a combination you aren't likely to find on sale. Once you are ready to expand into browns and grays, the eBay offerings get much more promising.
Thank you. I'd gladly buy a brown one or any other versatile colour. It's just really hard to find one that fits, is versatile (i.e. not celery green or red) and doesn't have any eccentric detail (i.e. flap patch pockets). I might even buy the blue one and wear it all-year long until I find better options. The long term plan is going bespoke but I'd rather try a few things first, so I'll know what I want.