I just don't get it. I don't really rely on the ship for much damage injection during attacks on my island, but it can be a good toughness "sink" to absorb attackers' time (and keep 'em away from my loot). But the main value of a ship for me is collecting materials for LPs; the economics of exploring the maps with very expensively trained crew for meager booty is pretty bad. So, will a level 6 or 7 ship travel a plotted course any faster? Will it contribute to speedier defeat of sea monsters, navy, ghost ships, etc? Will it contribute to "damage" to these targets in the case the crew's total damage profile is stretched a bit thin for a plotted string of attacks? ...Just asking...
Lv 7 ship has like 7k more hp than lv 5, and does considerably more damage, both of which are increased even further with LP that boost all defenses. The outer cannons can shoot slightly further as well. The lv 5 ship already mowed down unprotected gunners pretty fast, and lv 7 does it even faster! As for exploration, its impossible to reach the corners of the Eastern Seas map without a lv7 ship. It doesn't seem to help in actual sea battles, but Ship 5 will only be able to explore like 20% of the map.
