Seriously, I know they were utterly worthless before, but now they might be a bit OP - they literally make all other naval units before them obsolete the instant they appear. The naval unit just below them is worth 25 power. Ironclads are now FIFTY power. 50! Only 5 less than Destroyers! And they can enter ocean now! They are COMPLETELY invincible against wood ships (as intended, I imagine, since they actually were), they move double speed in coast, and they have a built-in 33% bonus to attacking coastal cities, making them even stronger than Artillery for cities before you get ANY promotions, which are each an additional 33% themselves. Granted, if your coast cities only have one naval tile next to it, you're pretty safe unless you face one that has promotions, since they seem to take tons of damage from city bombardment, but if your city is exposed to the sea, these things are like naval battering rams without the downsides, better than anything in its era for attacking cities OR navies. If you get one to City Attack level 3, it can take off 1/2 of a city's health in a single hit. They can one shot wood ships with only a single promotion. I'm not kidding when I say invincible. I had 5 Privateers attack a level 0 Ironclad, didn't die, it got an upgrade, I gave it bonus vs. ships and it turned around and one shotted the first privateer I pointed it at. It was at 20 HP when I ordered it to attack, it didn't even lose half of that in the attack. The Priv was at 55. My Admiral wasn't even nearby. I lucked out and became allies with all the city states while conquering Germany and Hunland, and I seem to have like 50 sources of coal as a result, so I have a MASSIVE fleet of these just tearing everything to pieces. I also lucked out by having all the AIs put their important cities near the coast. Looks like game over. They all had huge navies before my ironclads started one shotting everything. Their only downside is they only have a move speed of 3, but since it's not "half speed in ocean", it's "double speed in coast", these things move 6 speed on the coast, and for every movement speed upgrade you get for your navy, it gets double benefit. Great Lighthouse + Naval Tradition means they move 10(!!) speed in coast, and since they get the melee ship upgrade line, every time they attack a coastal city, you get gold.