i agree with you on this point however an auto log feature i don't think should be in the game, it would be better if there was a map scale so you could use a tool to measure out the distance of one nautical mile in game and then do some basic distance calculations or something similar.
and yes they had the tools to give them a rough fix on their position but it was not accurate to a few meters, using a sextant the position could wary between users by several nautical miles (Even by experienced users) that is why they used dead reckoning meaning they used speed and course and time to calculate their estimated position and plotting this into a chart, not to mention tide and current charts but that is a whole different ball game.
but yes i agree with you that OW navigation would be a great addition, i would personaly want a proper bearing compass in the OW map (M) so you could take out a simple heading.