Underwater Topography
 

Aside from the depth contours on Bizer maps, has anyone ever seen a map of the underwater topography of the Lake? I've always wondered what it looks like down there.

Mike

I have always wondered the same thing! I would love to see a map showing the bottom of the lake, minus the water....

other than Bizer, the last two versions of the Navionics chips provide very detained mapping of the bottom. The lastest version is accurate to like 5 ft. This chip will run in any Navionics compatible GPS.

Navionics Map
 

This sample of my Navionics map seems to be a bit more detailed for underwater topography.

I did a little investigating when I spotted that they named some of the under water mountains in the lake. The person I contacted at Navionics was sure that USGS was the one to name these features. This is the response that USGS sent back:

Underwater features generally are not shown on USGS topographic maps. I took a look at the USGS Geographic Names Information System (GNIS) database at U.S. Board on Geographic Names and found no features by those names listed in New Hampshire.

I am forwarding your inquiry to the GNIS Manager, for further response.

(I have not pursued the issue any further.)

That's a pretty cool graphic! The one area of the lake I was particularly interested in was The Broads. I've always been curious why the depth goes from 180'+ to 30' so quickly. Thanks for sharing!

I have a pretty good feeling that Bizer knows where those names came from.

The map that RG scanned above is available at

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Winter harbor
 

RG great map. Is there a set of the lake? I'm interested in the enterance to Winter Harbor. Everytime I drive thru there my depth finder goes crazy.

Navionics Map
 

FLboater, my attachment is actually part of a folded, vinyl-ish, whole lake map. I chose that area because I was interested about where the underwater mountain names came from. From the above e-mail that I received from USGS, I suspect the name are not official.

This map is quite interesting for studying and I look at if often. I'm glad R-Guy snapped it up when he saw it at County Stores hardware in Milford. I hope the local retailers that are listed above have a lot of copies! Thanks Rattlesnake Guy.

When I get back to the camp, I can get a better scan of the entrance to Winter Harbor and send it along to you.

Mt Celia?
 

Cool map RG, gotta get me one. This map got me looking at the depth recordings on my Bizer. I found an area that I travel frequently that I never thought about being shallow. Half way between Jolly and Sandy in the Broads it gets down to 12 ft! Can I name it, huh, huh, can I, can I?

Flboater, I'm curious too. I've noticed that during a NW wind the swells build up at the entrance of Winter harbor....even bigger than the broads.

Got The Map
 

I bought the map yesterday at Fayes. I think the Winter Harbor Entrance thing is related to how you cut the entrance. The 2 side points sand bars are larger than I thought.

Great map.

Bathymetric map from Navionics
 

Neither Fays not Silver Sands has the bathymetric chart posted here. They are made by Navionics but marketed by MapTech (508-990-9020).

Price is $14.95 and they have a limited number in stock; Re-print set for about Feb. 2011. At some point they will contact Winni marinas and stores etc. and get them out that way also.

The Map I bought at Fays is a navionics hotmapes premium.Lake Winnipesaukee