Garmin 478GPS has charts?

[Keyne]

Trying to find a good GPS (nonfixed mount) and noticed the Garmin 275 and 478. The only difference I can see in the two (other than price) is the XM radio and maybe the charts that come pre-loaded. Looks like the 275 only has general marine charts... not the true detail so you would have to buy a card. However, it looks like the 478 includes the good charts that you could actually use for coastal navigation because they have enough detail... its hard to tell from the specs and pictures because they always discuss the upgraded cards (if you look at fine print on th 275 it says with optional blue chart). Anyway, trying to figure out what you get out of the box vs with upgraded chart cards. Any help would be appreciated.

K

[sailingdog]

What is the Garmin 275... There isn't such a model AFAIK... The 276 is an older model and uses the BlueChart software for marine charts... and the charts have to be unlocked area, by area, and downloaded into the unit using a PC. Areas not downloaded only have general marine data.

The 378 and 478, are two generations newer, since the 276 was followed by the 376, which was the first unit to support the XM radio weather.

From Garmin's website:

Preloaded and Portable
From curbside to dockside, the GPSMAP 478 has you covered — no downloads or computer required. Its built-in marine charts utilize the latest BlueChart® g2 technology and feature coverage for all U.S. coastal areas, including Alaska and Hawaii. Our g2 mapping technology offers a smoother, more fluid presentation on your screen.

The 378 has the inland data preloaded.

However, all three units, the 276, 378 & 478 can also accept BlueChart data that is unlocked from the CD and downloaded on to their data cards. You do need a proprietary Garmin Data Card programmer to do this... I'm not sure how good the 276's compatibility with the newer BlueChart G2 data formats is though.

Remember, that the charts pre-loaded on to the ROM in the 378 and 478 are from a fixed point in time and do not include any NTMs after the date the data was fixed, so may not be completely accurate to the areas you are sailing in.