Spacekitty
Recently Resurrected Divine Feline Entity.
Based on research, going up a river IS possible with old ships, but very dangerous (as you can scrape against the bottom even with larger rivers) and EXTREMELY slow, especially up current.
I'm not sure how big this River is, but my men found a shallow area fit for flat bottomed boats so my guess is that it is not big enough for a Man O' War.
I'm not sure how big this River is, but my men found a shallow area fit for flat bottomed boats so my guess is that it is not big enough for a Man O' War.