I saw a Belkin last week. It cost only a little less than the GPS...
Well, that would work if it was a software issue or even a connector issue.
First off, SeaClear is free software, and unsupported, so you have to learn to work with it , not against it. You can always ditch it and spend the big bucks for a charting program.
Poor old Seaclear is just looking for your GPS on a serial port. The fact that it's not there is a hardware issue or an operating system issue, not Sea Clear's. If your Laptop has a serial port input, and your GPS came with a serial cable, plug it in, or at the very most just buy a cheap adapter to make it fit, and you're done.
Next, If your GPS came with a USB output, it doesn't help as SeaClear won't look at the USB ports for a GPS. Unless the GPS came with emulating software, in order to emulate a serial port. If it did, you're done.
Lastly, if the GPS came with a serial port cable and your Laptop doesn't have a serial port, You have to convert the GPS to a USB connector. The serial port to USB adapters (Belkin) sold actually have an intergrated circuit (IC) in them to translate serial communications to USB to and they include software to emulate a virtual serial port (com1, com2..etc). They come with a separate operating system driver to connect it to the operating system. In my case this was Windows XP but it works fine under Vista.
If you're commenting that a good charting program isn't worth the $15 for the Belkin adapter... I don't know what to tell you. Maybe to go spend $100.00 instead?
At least then you can yell at customer support if it doesn't work ...only if they speak English of course..
Incidently, To make it work took less time than it took to type this.