I think a bit later ship could fit Lanun better. How about holk - a cog replacement that can enter ocean squares but has a low (2% ?) chance to sink if there. And I do not mind making FfH more of a naval game... In fact, I would like to, just as I have expanded it towards late medieval/renaissance (and plan to continue if there is anything worth adding/fitting).
Holk? Did you mean hulk? Not sure why you'd want them as they don't move. Looking at the different types of ship names, I'm not quite sure how to go. Looking at what a cog is, I'd say the 'better' Luann replacement would be the Chinese junk but that hardly fits their image.
From what I can tell, the evolutionary line of ships goes cog to caravel to carrack to galleon. After that it seems all the ships seem to switch over to the fore & aft type ships of all sizes that are 'basically' the same ship in different sizes and number of sails (sloops of war, brigs, barques, corvettes, frigates & clippers)
Seems to me that the Luann need to be the Portuguese and perhaps have a carrack instead of a caravel since the carrack is listed as being more sea-worthy than the caravel which was designed more for coastal work (such as skating down the coast of Africa) than actually going any distance over open ocean.
Actually the problem with FfH ships is that the galley design was the predominant ship for a long period. The difference was the medieval galleys (or galleass (large) galliot (small)) was that they started mounting guns. So without some magical equivalent of canons, you really wouldn't get that much difference in offensive power between ships. Obviously as ship designs allowed for bigger ships as well as more maneuverable ships the ram would become useless. So until canons are invented, without a magical equivalent, you'd pretty much be reduced to having mages on your ships which pretty much what a Arcane Barque is.
Not sure how people want to do it. Perhaps a new tech of Naval Weapons could be thrown in. That way you could have something like this.
Early Ships - most flat bottomed ships with oars
Galley - transport/merchant (coastal)
Trireme - combat (coastal)
Cog - transport/merchant (coastal but can go into sea tiles with chance of sinking)
Galleass - combat (as with the cog)
"Medieval" Ships - Switching to full sail capable
Caravel - transport/merchant (coastal/sea safe - good chance of sinking in ocean tiles)
Carrack - Luann UU - As with Caravel but with much less chance of sinking in ocean tiles.
Galleon - transport - Small chance of sinking in oceans.
War Galleon - combat - As with Galleon. Actually, according to Wikipedia, most Galleons were used for combat as they were actually cheaper than the smaller but more seaworthy carracks but oh well.
Late Era Ships - Switching to the sleeker hulls and more complex rigging with no chance of sinking in oceans.
Barque - transport/merchant (fast)
Frigate - combat (light and fast)
Ship of the Line - combat (heavy and slower)
Optional Later Era Ships
Clipper - transport/merchant - Putting the fast in fast.
Man of War - combat (Final phase of the sailing combat ship)
I'm thinking that when it comes to ships, an idea from basic Civ (or is it from Rise of Mankind?) is that later vessels get bonuses against earlier vessels. I'm sure this could get played with a bit, but it seems like this to me.
Trireme is to warrior
Galleass is to axeman/swordsman
War Galleon is to Champion
Frigate is to Beserker
Ship of the Line is to Phalanx
Oh, and I'm also thinking that the whole sea monsters need to be revamped. Either have the critters get nastier as the game progresses like the barbarians do or split the monsters into weaker coastal ones and then have sea and ocean going ones that are tougher...although I'm not sure how you'd keep the latter from going into coastal tiles.