I can help with where the Seneca River and Cayuga Lake meet - Here's the text to make a kml file for Google Earth. Copy it and paste into NotePad, then save as a ".kml' file. As long as Google Earth is installed on your computer, double clicking this file will open Google Earth and take you to the spot on the map. This the location of a free launch run by the state. Concrete ramp with dock.
Code:
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2" xmlns:gx="http://www.google.com/kml/ext/2.2" xmlns:kml="http://www.opengis.net/kml/2.2" xmlns:atom="http://www.w3.org/2005/Atom">
<Document>
<name>KmlFile</name>
<Style id="sn_ylw-pushpin10">
<IconStyle>
<scale>1.1</scale>
<Icon>
<href>http://maps.google.com/mapfiles/kml/pushpin/ylw-pushpin.png</href>
</Icon>
<hotSpot x="20" y="2" xunits="pixels" yunits="pixels"/>
</IconStyle>
</Style>
<Style id="sh_ylw-pushpin0">
<IconStyle>
<scale>1.3</scale>
<Icon>
<href>http://maps.google.com/mapfiles/kml/pushpin/ylw-pushpin.png</href>
</Icon>
<hotSpot x="20" y="2" xunits="pixels" yunits="pixels"/>
</IconStyle>
</Style>
<StyleMap id="msn_ylw-pushpin17">
<Pair>
<key>normal</key>
<styleUrl>#sn_ylw-pushpin10</styleUrl>
</Pair>
<Pair>
<key>highlight</key>
<styleUrl>#sh_ylw-pushpin0</styleUrl>
</Pair>
</StyleMap>
<Placemark>
<name>Cayuga State Launch</name>
<LookAt>
<longitude>-76.73193030081211</longitude>
<latitude>42.94582646792357</latitude>
<altitude>0</altitude>
<range>560.7714377259829</range>
<tilt>0</tilt>
<heading>0.1025062844525144</heading>
<altitudeMode>relativeToGround</altitudeMode>
</LookAt>
<styleUrl>#msn_ylw-pushpin17</styleUrl>
<Point>
<coordinates>-76.73374619665144,42.94630776058528,0</coordinates>
</Point>
</Placemark>
</Document>
</kml>
Additionally, you can hop on over to UNYF and ask-away. We've got a bunch of members from the Rochester area that should be able to point you at launch sites and some hot-spots closer to where you're gonna be staying.