It is surrounded by water on all sides with the San Francisco Bay to the east and north, the Belmont Slough to the south and the Seal Slough and O’Neil Slough to the west. There are two places where the water can be blocked and selectively allowed to pass. One is the intake dam on Third Avenue. The other is near this cache’s location, which is the only place where land connects Foster City to the mainland making it a peninsula instead of an island. Why do you think that is? I followed the water all around the city on foot when I first moved here to confirm its near-island status.
This cache is on a nice paved trail that follows Seal Slough toward the Bay. Going the other way, it connects to the San Francisco Bay Trail, a planned 500-mile walking and cycling path around the entire San Francisco Bay ( http://baytrail.org ). The Bay Trail passes through Foster City and by several of its very nice parks.
Although it is probably easier to get to this cache by land, you can also get quite near the cache location by boat. I have listed a nearby boat launch as an additional waypoint. Please note that this cache is not accessible from the Foster City lagoon.
The cache is an ammo box type container.
Congratulations to rosetyler31 and gooseville for FTF!