The National Oceanic and Atmospheric Administration (NOAA) has a number of maps showing the islands of the Chesapeake Bay, the location of sandbars and marshes, and the depth of the water at various points. These maps are available for viewing online or offline and will give you an idea of how everything is connected in the Bay.
You should first go to the NOAA historical maps page to see what is available and peek at a map or two online, then return here for the obscure instructions necessary to view the maps offline.
The site is at http://historicals.ncd.noaa.gov/historicals/histmap.asp. When you get there, enter 568 into the box labeled "Enter Chart Number" (M. K. Miles discovered this magic number). Press ENTER and the same page will reappear, but this time there will be a list of maps at the bottom. The maps you want are the Pocomoke and Tangier Sounds maps.
You will see two highlighted numbers to the right for each map entry. The first one is the "View" column. Click the map number and a new browser window will open with the map. Since the whole map is shown and totally illegible, zoom in like this: Click the "+" button at the bottom, then click the area of the map you want to zoom in on. Since you are now in zoom-in mode, further clicking on the map will zoom in at the same spot. To zoom out, just click the "-" button and then click the map. There are other controls available, and there is a nice help screen, but this covers the basics.
When you were at the NOAA site, did you notice the little link in the bottom right corner for "Mr. SID"? Go back there and click it (just click here for a direct link). It will take you to the page for the LizardTech company. Click "Download" in the bar near the top, then click "Plug-ins". Go to the product named "ExpressView Browser Plug-in (MrSID)". Since there is only a Windows version available, just click "Windows" right next to the little orange down arrow. That will take you to another page. Scroll to the bottom and click "ExpressView Browser Plugin". At this point the download of the plugin should begin. Follow whatever prompts you see on the screen.
If you are using Internet Explorer, all should proceed as above. If you are using a different browser or have your security settings too restrictive, you might get a page telling you that "Setup cannot run from this Web page". If this happens, just click the word "download" in the message "If you have trouble, you may download and run the self extracting installer." That should pop up a dialog box where you can save the file (exview_setup.exe) to your hard drive. Just remember where you put it and then close your browser. Find the file "exview_setup.exe" on your hard drive, double-click the name and let it install. Now you're ready for maps.
Return to the NOAA page, enter 568 to see the map list, and click on the second highlighted number for a map entry. This is the size of the file. When you click the number, the file will load and the plugin you installed will kick in. If you decided to download the file instead (by right-clicking it), find the file on your hard drive and double-click it.
The program runs normally in Internet Explorer, so however you get the file, Internet Explorer should open with the file ready to view. If you get a blank page and a security warning, allow Internet Explorer to run the plugin. You will find navigation controls at the top of the image. Zoom around as much as you like. When you find a portion you want to save in its current appearance, just right-click the image, click "Save As . . ." and give it a name. The file extension will be PNG. Double-clicking this filename later will pop up the image for you to view in your default browser, but without navigation controls.
Thanks to M. K. Miles for pointing out this site for us.