I always use 6 Destroyers, 5 Cruisers, and 4 battleships.

My strongest fleet was: 4lvl3 destroyrs, 4 lvl4 destroyers, 3 lvl4 cruisers, 5 lvl5 cruisers, 3 lvl3,3 lvl4,3 lvl5 Battleships, 8 carriers lvl4 with full carriage of aircrafts (half TB's, 25% fighters, 25% Navalbombers - all 3 lvl differenses); +some submarines.

But it was an day 40+, after weeks of cooperation with two other players.

yes, i was Australia. But even this is not strongest navy i had, it was only strongest single fleet.

on 100er 4x on day somthing +++, i had 20 carriers, 12 atom carriers, 15 Battleships, 6 Atombattleships, 100 subs, 20 atomsubmarines. And and and. But there i had more then 1 fighting group, several mobile naval bridges and and and. So my strongest single fleet is still with Australia on 25er historic.

If y'all want to play COW rounds where the naval units have greater impact, I suggest you play one of the 50- or 100-player maps, which last longer, necessarily involve ocean crossings by ground troops, and often provide more opportunities for naval warfare. In particular, the 50-player Pacific map was added to offer a game in which naval warfare often plays a much larger role than the smaller maps.

Navies on the smaller maps are usually a sideshow, where the outcome of the game is almost always determined on land and meaningful naval warfare is mostly limited to convoy escort duty and submarine intercepts of ocean-going convoys that someone has foolishly sent to sea without destroyer escorts.

It can be worth it, if you have really strong navy+airforces. 10+ highlevel carriers can destroy whole countries.