I've never heard of Boss speakers. That being said, I took a look at them via your link and have an observation or two. The first is, they don't tell you how big the speakers are physically. I'm guessing they're probably no more than 5 inches. Kinda puny. No weight on the magnets, either, which is an indication of how much quality is there.
Finally, and most telling, was the frequency response. 100-20K. That means just about no bass at all. (Are you listening Bose? Where's the bass?!)
If you're looking for quality sound while you're underway, I don't think those things will cut it, unless you aren't a fanatic.
Personally, I'd be more likely to try Poly-Planar or Clarion marine grade speakers. I helped some of my captain friends install systems on their big Vikings, Betrams and Hatteras fishing boats, and I honestly liked the Poly Planar speakers, and I am a fanatic. (I have a set of Altec-Lansing Voice of the Theaters with 15" woofers, 511 horns that are 24" wide, etc.)
Speakers are one of the places where, to a greater degree, you really do get what you pay for. If you like your tunes, you're going to pay to hear them properly.
Try this: Search Results Page
but stay away from the pyramids. They universally have a tinny sound.