After reading one of the previous posts about Garmin tidal info, I though I'd let you know about Lowrance. I'm sure you lot already knew this but it's taken me 18 months to find out that I could download some really useful stuff from them.
I have a Globalmap 3000MT which is now no longer sold, however, they are still putting updated software on their website which can be downloaded for free. The latest version available now enables you to see tidal flow and height infomation at most ports. This was obviously always there on the MMC card but is now viewable.
The other little beauty is an emulator which enables you to use the charts (via a card reader) on the pc. The screen shows an exact copy of the unit and you press the 'buttons' with the mouse. I can now plan routes and copy them to the GPS in the comfort of my house rather on the boat, in the garage. The other use of these emulators (for GPS's and all other kit) is as a 'try before you buy' tool. If my one is typical, they are exactly the same as the real thing. Also available for free.
Any of you Lowrance users out there who are as slow as me and did not realise this was available, or want to try some Lowrance kit, I can recommend it.