I hiked down to the Potomac just upstream from Georgetown the other day and sat for about 45 minutes as dusk settled. I had a couple of cans of beer and my binoculars. I didn't want to hike, so just found a level grassy bank and sat still. Spring was happening as I watched dozens of small cormorant flocks flying upriver in V formation. The wood ducks came out in pairs and foraged around in the mud and a lone osprey (the first i've seen this season) glided downriver, scanning the river's surface for any fish that might be unlucky enough to be visible.
On the more human side, I got to the river bank just in time to watch all the sculling teams practice going up and down the river, their coaches standing in little motorboats yelling into megaphones. Soon their practice was done and the water was quiet again. Just before I left, however, their was a ruckus and I saw two police boats, sirens blaring and lights flashing blue, heading upriver at top speed.
I really didn't know there was such a thing as police boats in DC. I will have to camoflage my beer a little better next time.