I also intended to remove it from the MilCS list, so this is a bug I've fixed for v117.1 beta.
Early boats awarded by MilCSs are better than ones we build ourselves, since they start with free experience otherwise unavailable to Triremes and Caravels. On maps like Continents-Plus or Pangaea-Plus, a fleet of at least three ships are necessary because they are a significant source of Great General points early in the game. Barbarians are much more likely to spawn on islands than the mainland since there are fewer units and cities on islands. Boats can also move faster than any land unit. I typically have 2 triremes, one each moving clockwise and counter-clockwise around my starting continent, with a third trireme killing off all barbarians within range around my territory.