Underwater Topography

[fltsimguy]

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

[NHKathy]

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

[MikeF-NH]

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.

[Rattlesnake Gal]

This sample of my Navionics (http://navionics.com/NavionicsNews.asp?ID=217&ArticleYear=2006) 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 (http://geonames.usgs.gov/) 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.)

[fltsimguy]

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!

[jrc]

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

[Rattlesnake Guy]

The map that RG scanned above is available at

<TABLE border=0 cellSpacing=0 cellPadding=0 width=746><TBODY><TR><TD width=2></TD><TD height=300 vAlign=top><TABLE border=0 cellSpacing=0 cellPadding=8 width="100%"><TBODY><TR><TD vAlign=top width="64%" align=left>
<FORM method=post action=/NavionicsDealerSearchResults.asp><TABLE border=0 cellSpacing=0 cellPadding=0 width="100%"><TBODY><TR><TD align=left>Gilford</TD></TR><TR colspan="2"><TD><TABLE border=0 cellSpacing=0 cellPadding=0 width="100%"><TBODY><TR><TD style="PADDING-TOP: 5px" vAlign=top width="5%" align=left>FAY'S MARINE STORE </TITLE> (http://www.faysship.com/)
</B>3 Varney Point Road
Gilford, NH 03249 UNITED STATES
Phone: 603-293-0808
Fax: 603-293-0022
Email: dave@faysboatyard.com (dave@faysboatyard.com)

</TD></TR><TR><TD style="PADDING-TOP: 5px" vAlign=top width="5%" align=left>SILVER SANDS MARINA </TITLE> (http://www.silversands.com/)
</B>Rte 11B, 103 Weirs Road
Gilford, NH 03249 UNITED STATES
Phone: (603) 293-2115
Fax: (603) 293-2086
Email: jg@silversands.com (jg@silversands.com)
</TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE></FORM>
</TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE>

[KBoater]

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.

[Rattlesnake Gal]

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.

[SIKSUKR]

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?

[SAMIAM]

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.

[KBoater]

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.

[Diver1111]

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.

[KBoater]

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