How many trade ships i need?

[Это не шоколад]

for one trade spot

[Telvido_cat]

10 is max

[Hat8]

You should fill up trade spots with trade ships.

[carlc]

So, combining what the other two correctly told you....each European trade port can hold 10 ships (each fleet also can only be 10 ships, though that perhaps is only on small?). So, at each port you can have up to 10. They can fight a bit, so you could go with just 10...but I like to leave at least one fighting ship there too.

Thus, to get your answer, it depends on how many ports you are trying to trade into. Two ports...up to 20 trade ships is what you should build. 3, 30...and so on.