Without some experience with these in a couple of systems it is really hard to determine that. Here is what I mean.
So as an example, in an off-shore console boat with giant expansive gunnels (provided they are not foam-filled), you could have several pair of 880s and eliminate the need for a subwoofer because the bass of a true 8.8" speaker would offer so much surface area, and it's a particularly hard boat to load with sub enclosures. In another application, in an off-shore performance boat, when typically standing up in bolster chairs, it is always a challenge to get enough from the front cockpit speakers. We often try to double or triple up on these in a cluster if the boat cooperates. A single pair of big 880s would certainly solve this challenge in a more effective manner.
We definitely know that in an open field environment it's all about the maximum surface area. So bigger is usually better.
And for great sounding bass, you are very dependent of the coaxials or components for tonal construction. When the sub over-runs the collective coaxials/components midbass contribution, the bass accuracy begins to instantly suffer (not that everyone has bass accuracy as an objective). So a larger midbass driver can offer better bass sound quality and offer a more seamless integration with the sub because it can keep up and compete.
Now the potential downside and the challenges in a typical inland towboat, even a big one:
This 880 has a big cross section so few towboats will have the flat surface area for mounting. The JL Audio 880 also is a bit of a monster in motor structure and depth so it will bottom out against the hull anywhere there is a shallow gunnel.
The smaller JL Audio M770 has fantastic midbass when correctly powered and is a well-balance speaker from midbass to highs. As you transition to a larger speaker, especially a 2-way speaker, the increased midbass cone diameter tends to limit the upper frequency response. Perhaps with more output and more midbass extension from a speaker of larger dimensions, we are giving up some accuracy in the heart of the midrange. Or, with a larger tweeter are we giving up a bit of detail on the very top end or off-axis dispersion? We just won't know what that ideal balance is until we get a few of these under our belt. At this point it's still a little speculative.
Personally, I try not to leap too quickly at the newest thing until I have some experience to base an opinion on. Not much help, I know, at this point, but those are my early thoughts.