Just wanted to quote all of this
I love the manual navigation but the lack of tools to plot your course or a scale on the in-game map is a real problem. It's easy to sail from point A to point B with a single bearing and the wind in your favour, however if you need to repeatedly tack or you get distracted on a chase you can end up very lost indeed.
I'm quite happy to do all the calculations (bearing, speed, time, etc) as I travel but we need a way to plot our information on the in-game map. If no tools like this are added or planned by release 1.0 then I'll write an external program myself to do it, but that really shouldn't be necessary. Silent Hunter 3 is the best example I can think of for the kind of thing we need.
I also like the idea of being able to get a bearing once or twice a day, with a margin or error of course perhaps modified by officer skill, so you can make corrections to your calculations.
If anything this will add even more skill to navigation (right now it's very much "point in a direction and don't turn until you reach the next land mass") as you will be able to keep track of your course more accurately and bringing your ship/fleet into harbour as directly as possible will be a great feeling of achievement.
I did something like this last night when I needed to sail directly into the wind on a non-coastal voyage across open sea (10+ mins) where I timed each leg as I tacked using a stop watch (in fact I used a pocket watch from my collection with a ship emblem on which was rather fun!) and it was very satisfying to come across land very close to where I was aiming. However had I had to travel further and longer and so more likely with a changing wind or distractions of enemy to chase then this simple method would have broken down and I'd have also needed a way to drop some markers and lines on my map as the legs were no longer even.