Historical Map and Chart Collection
From the Office of Coast Survey, includes NH historical nautical charts.
National Ocean Service
Access to online nautical charts.
NOAA Nautical Chart Catalog and Chart Viewer
Can view any of NOAA's 1000+ nautical charts, as well as download NOAA's general use charts in three different raster formats.
NOAA's National Ocean Service
Access to tides and currents information.
New Hampshire Tide Charts
Commercial site with links to other New England tide charts.
WWW Tide and Current Predictor
Select a region, then select a site in order to generate predictions.