At 24 25 629n 80 44 981w there is a 350 ft tall pinnacle, It doesnt show on the furuno bathy charts. It seems the charts show holes well and ignore humps, In south florida we fish humps.
The standard C map charts show the humps but no detail for bottom fishing. In fact cmap shows all of the humps in the area furuno bathy charts show none , It makes no sense! these are huge features.
The hump is shown on the free NOAA raster and vector charts. It is also shown on the C-map Jeppesen chart for that area.
The data used for the free fishing chart is from a diffrent source (as is the depth shading 3d data) and they do not reflect that hump. Thanks for the infomation. I have reported that location to MaxSea/MapMedia.
Talking with MaxSea; the data in that area is debatable. Maybe you can provide some screen shots and lat/lons to our normal support folks (http://www.FurunoUSA.com – SUPPORT – ASK FURUNO A QUESTION) next time you are in that area. Here is the supporting data from MaxSea.
Here is a little bit of explanation where the MM3D 3D data (used for Depth Shading) is coming from.
Near shore, the 3D data is extracted from the vector charts (S57 charts). In shallow water it is MUCH better to use the 3D from the vector charts because it is the most up to date and usually you have enough depth soundings and contour lines on the S57 charts to create a nice 3D database.
However, in deeper water, the density of the Vector charts soundings decreased rapidly (because over 100ft of water are not areas that are a threat to navigation, so the depth information on the chart is very sparse). So, in deeper water, we rely on another 3D source (the "Coastal Relief 3D database" from NOAA). The Coastal Relief is a huge database that combines various surveys. You can read more about it there: http://www.ngdc.noaa.gov/mgg/coastal/crm.html
In theory, this database offers much more accuracy especially in deeper water.
So really you have both data methods in your machine. Based on what they are saying, the fishing and 3D depth shading is most likely the better of the two in the deep waters. Look at the data it looks like that hump is more of a peak off of an underwater ledge. MaxSea said they are ready to consider any factual data you can provide them. We would gladly pass any information you can collect. (http://www.FurunoUSA.com – SUPPORT – ASK FURUNO A QUESTION)
When I go to the Furuno website / Products / NN3D / Charts for NN3D / USA East Coast, the "Narrow Results By" options include:
-- 3D/Bathy Data (8)
-- Bathemetric (1)
-- 3D Data (3)
I thought "Bathy Data" and "3D Data" meant the same thing, but the above choices seem to refute that. Can you please explain the difference between the two? From your explanation above, it seems that 3D data is for <100' and bathy data is for deep water fishing.
As a sailor, all I am interested in is high quality depth shading in shallower water. What data package gives me this info?
Under this thread we were mostly discussing the included "Fishing" bathy charts. This chart is used when you choose "Fishing" under your CHART finger from the roto-key. This is not to be confused with the spot bathy provided by the charts or the 3D depth shading bathy provided by the 3D data file. In waters less than 100 ft, you should be using the spot soundings/markings on the chart in addition to the 3D depth shading. Since the water bottom changes all the time, you should also refer to your navigation depth sounder and other "Tools".