The deal with
current charts concerns mostly updating change to nav aids I would assume. Although Digitial charts are expensive for a region, to buy a current set of charts for that same region would probably cost a heck of lot more.
And if you have paper charts... those too could be outdated if new nav aids have been added moved or removed.
I think if you are going to sail in unfamiliar waters you should obtain the most current information for that region before setting out... In the end it is a small
price to pay when you consider the cost of everything else and what level of
safety this provides.
Driving an autopilot on a sailboat often makes no sense at all because one has to trim and it is rather rare to be able to sail rhumb line courses from waypoint to waypoint. But that doesn't mean you should hand steer. Once you have established the course to a waypoint you can often set the autopilot to that course, trim the
sails and trim and trim as long as the
wind is in a favorable direction. Once you can't fetch the waypoint because it is to close to the
wind...or say dead down wind,
steering to the waypoint by the autopilot is useless.
Now you have to do some plotting and planning and tack or gybe and so the
concept of a position fixer driving the autopilot is uselesss. You have to set a course, trim and then enter a new course tacking or gybing back and forth across the rhumb line.. that is if you have a fairly consistant wind angle.
But there are favored tacks because of current and predicted wind shifts and so on.. and if you plan them right you might find yourself do best by tacking on headers for example over to the favored tack and hopefully follow a lifter right back to your rhumb line. These are all tactical navigational decisions that a poisition fixer driven autopilot cannot do without YOU inputing the headings.
No one should have to suffer the tyranny of the
helm, so autpilots to make great crew, but the idea of dumping a bunch of waypoints into a
GPS and letting it ghuide you along from one to the next has nothing to do with sailing.
You could do this under
power... and this preciusely what
power boats do and makes one wonder if they even bother standing watch.. since the GPS autopilot rigs can do rhumb lines pretty accurately.
I like to caution people with the following story.
I sailed many tme between
English Harbor
Antigua and Des Hais, Guadalope in both directions. Since the angle of the prevailing winds allows one to sail a rhumb line in for each coarse... you can enter the waypoint which is perhaps 50 miles away... set the
sails and pretty much let the boat sail you there. Ain't those trades great!
What I found one day when I was preparing lunch down below was a sailboat passed by right next to my
galley port. I
race to the
cockpit totally freaked to have such a close encounter 25 miles from land. But as I look forward I saw a line of sailing vessels headed my way in what looked like a line of
single file.
We we all on GPS driven autopilot reciprocal rhumb line courses. Since that time I realized that this was essentially a highway in the sea between the two
ports and collisions were possible at anypoint on that highway because vessels were departing each port at all hours of the day. The most common collison point was obviously mid day as most sailors start out early for a daylight arrival in the evening.
This IS the
danger of navigating rhumb lines between commonly used waypoint, using autopilots and not maintaining constant watch... In my case I
single hand and so I need to leave the ccockpit such as above when I was perparing lunch... but now I am much more cautious and will pop my
head up and
survey the horizon as often as possible when I am on these highways.
OK there are no roads out there as we know on land.. but there are now virtual ones made possible by GPS and autopilots... and there is no
concept of separation there... so sailor beware!
Jef
sv Shiva
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