Depends.....
.....on what you really want to do.If you want a real navigation tool that you can use at the helm while sailing, then I have to agree with the previous post; forget the PC and go get a chartplotter. The problem with the PC is a display that you can really use at the helm. If you want a display at the helm, then be prepared to pay upwards of $2.5k for a daylight-visible, waterproof display. And that is after buying the computer and the software! Right now, $850, or even less, can get you a very useful chartplotter, including charts. That said, we did buy Nobeltec Visual Navigation Suite 2 years ago, and it really is a great package. We use it for voyage planning on our home PC, and we have even brought it aboard on a laptop for planning purposes while out on a trip. Yes, we do use it, but we have never used it for what we originally bought it for. We had the "grand vision"; a completely integrated PC-based navigation system, display at the helm, radar overlay right on the chart, yadday, yadda. What we found is that all of the technology pieces are not really there yet, and what is there gets very expensive very quickly.So, with a bit of disappointment, we bought a chartplotter, and we really use it at the helm, and it's great. We ended up with a Garmin 182 black-and-white with the new Garmin Blue Charts. Be wary of color screens; visibility in real on-the-water conditions can be tough.Good luck with what you decide to do!Carl and Jules/v 'Syzygy'