Clearly because the creators of the game felt no need to make John swim. It has nothing to do with his character. How dare you assume he is stupid! :Plots of people couldn't swim 100 years ago, no biggie.He suffers from severe mental retardation.If you can think of a better way to explain away delaying access to two big, neighboring land masses without invisible walls, be my guest.not many people knew how to swim in those timesNo, people didnt know how to swim back then because people were so busy working and had little to no time off so swimming really wasnt a big interest.No, as a matter of fact, many people back in the day didn't know how to swim. Those that did weren't very good at it. R* probably didn't want Marston to swim because they didn't want you entering Mexico early.It wasn't built into the game, sort of like the earlier Grand Theft Auto games.No. At the time, not many could swim. Also, you mainly fall in the water on a horse, and most horses cannot swim.many people before the 20's did not know how to swim it just wasn't considered a necessary skillTotally. :PYes.he carries so much gear that he is too heavy and he drowns, while in the grand theft autos when you can swim the protagonists only wear loose clothing and only carry one item at a timeyesI ansWer your question with another question, why does he have to swim?Marston doesn't need to swim, He lassoos and hogties the water.He probably could in real life but if the team added he ability to swim on the game it would ruin it! He probably could in real life but if the team added he ability to swim on the game it would ruin it!yesSure why not?he can swim but all the "water" in red dead is actually poison. would like to see u swim in poison.