Navionics map upgrades help

I am considering getting a Navionics map upgrade for my humminbird 581I HD DI combo unit. I can't tell what is the difference between the marine and lake, hot maps and gold editions. Does any have any of these maps? What are the pros and cons? I haven't used it enough to know what all it can do, but I do know I went out in the delta and the built in map didnt show where the north end of shag slough turned and headed over near the deep water channel. This leads me to assume there are other features that will not be on my map. I like that the marine and lake map covers off shore as well for navigation. The features that are supposed to help with fishing I don't know enough about. Do the hot spot and gold product have detail for navigation? What about off shore. Thanks ken

I got a Navionics add in map called the Fish N Chip and it has a tone more info on it than the really minimal map included with the unit.

I haven't even been out yet this year and have trouble remembering the details but below I will include the text of a PM I traded with another member earlier this year when he inquired about my Fish N Chip experience, it might give you something to go on.



OK….so I had some free time at work yesterday and did some research.  It was kinda like crawling down a rat hole if you know what I mean.

The “Fish N Chip” has been discontinued.

I think there are a few available from Amazon resellers for about $300,  Mine was about $190 when new. There may also be some available at other online retailers, not sure I'd buy a discontinued item.

Navionics has included the fine detail of the “Fish n Chip” in the “Platinum Plus” chip which is NOT compatible with the 788ci.

Saw a note from a Navionics rep online that said a new product called “Navionics+” would be coming out this spring with similar info but I haven’t found it for sale.
 
Then I found a press release that mentioned the Navionics+ chip.

  http://news.thomasnet.com/companystory/Navionics-Announces-Navionics-and-Navionics-Updates-20003779

A search online for  Navionics+ led me to the chip called the Navionics Update Card which isn’t  the same thing. But I couldn’t find a Navionics+ for sale anywhere.

Finally I called my local West Marine and they can order them (the Navionics+ for $179).  And the girl said they still have some Fish n Chip chips in hand. Two things I forgot to ask were is the fish n chips they have the West Coast version, and is the Navionics+ compatible with the 788ci. As of yet I haven't seen a compatibility chart for the Navionics+

Other than that:

My  memory fails me about exactly what happened when I put the chip in my unit. Seems to me that the chart views just showed up with the Fish N Chip charts instead of the Unimap (much better than the OEM chart) and that my way points did show up on them, but my memory is crap (and I haven’t been in the yak since November so no recent memory joggers for me).

If you go to the humminbird website and go thru the contact info (by email) I've found their tech help to be pretty good.

They’re not cheap but the map I got with the Fish n Chip was so much better than the OEM.  If the Navionic+ chip works in a 788ci it would probably be worth it compared to the Uni map that came with the unit.

Here is the most informative thread I found, it’s 2 pages long, be sure to read the last couple of posts on it on page 2. 
http://www.stripersonline.com/t/859070/navionics-fish-n-chip

Thanks for the info. I decided to go with the marine and lakes. Cabelaes shows it as compatible with my unit and I think navigation is the most important map feature.