I agree wholeheartedly with Ash here. Perhaps small ships are less fun to look at, but they are DEFINITELY more useful.
I have built perhaps some 600-700 missions through all the years, and I've used big, hefty battleships in perhaps
2 or 3 of these. At the same time I've used the "Cargoship, dry" in probably ALL that involved some water. After that the Russian trawler with the single gun.
If you want WW1 type big vessels BTW you halso have the two Finnish armoured cruisers, Ilmarinen and Vänemöinen. So there actually ARE several WW1 era naval ships around.