It's possible to beat the Eurotrash on the high seas while you're like 15 dip techs behind if you've got at least 3-4 times as many heavies in your fleet as their entire fleet size (including all their transports, lights, and galleys). In naval battles each ship in the fleet randomly picks a single enemy ship, inflicting hull damage based off cannons and hull (among other things) and morale damage based (probably) off maximum morale. A ship is rarely in danger of sinking if it still has even 0.5% morale left (unless it gets simultaneously targeted by multiple heavies) but when it runs out of morale, a ship will no longer fight at all and will take hull damage extremely rapidly. By having a much larger fleet than the opponent, most of your ships won't take any morale damage, while being free to gang up on the enemy ships that are distracted and sink them with the pure hull damage of heavies (even lousy early carracks). So even a disgusting English navy with 20 heavies + 20 others, naval ideas, and dip tech 22 can usually be sunk by a dip tech 3 navy many times the size, if you can afford the astronomical costs of that many heavies.
There's also a trick to prevent any of your ships from being sunk in battle. If you divide your navy into individual fleets of one ship each, and then watch the battle carefully for when a ship runs out of morale, you can order it to retreat individually, recover morale/hull at the tick of the month, and then order it back into the fight. It requires tons of micro, but it can be used to win battles that'd otherwise be lost, or prevent any ships from being sunk in easy victories.