I was lucky enough to get a RC400 and a Garmin 76CS as wedding presents in August 2005.
There seems to be a number of discussions on various forums about the pros and cons of these units so I thought I would give my experiences of using both while sailing in the English Channel for the past 2 years.
Garmin 76CS – the Pros:
1. Although I have the Raymarine RC400 mounted at the helm – the Garmin can go anywhere with me – to the Marina office, to the cafe, to another yacht etc.. its truly portable because the batteries last. Unlike the RC400 the batteries last for at least 24 hours of use.
2. It has its own GPS so it is another backup for position data separate from my main GPS / C120 setup.
3. The BlueChart software is loaded from the laptop – you dont need another copy like you do for the RC400. The software auto loads all relevant charts for the route you have planned. Interfacing to the Garmin BlueChart software on my laptop is easy and always works perfectly.
4. You can use it in the car too – there are comprehensive charts for Europe including detailed maps of all major cities.
5. Garmin continue to manufacture and support this unit. There is a tremendous amount of software and add-ons for it on the Net. The latest 76Csx uses the latest SiRFstarIII chip set
Garmin 76CS – the Cons:
1. The screen is hard to see in poor light, it is quite dim and you need to press a power button to turn the brightness up – quite awkward when you are wearing gloves or have stubby fingers like me.
2. The buttons are above the screen – why ? They are small and hard to press accurately.