This section of the C&O starts off with what is possibly the most scenic part of the entire towpath, so it's a good thing I had done it before and didn't get distracted by side trails or by too many photo stops!
Since this was right after the time change, I started a little later than ideal - at least for Old Angler's parking area, which fills up fast. But I managed to get a spot, and headed west through the crowds. Although sunny, it was quite windy; my hat tried to blow away.
The trail itself is very pretty heading to Great Falls, and of course Great Falls is, well, great. The best views of it aren't had from the C&O Towpath itself. Normally, I would spend some time detouring here.
Once past Great Falls, the crowds thinned out considerably. Most of the rest of the trail to Pennyfield Lock is what I think of as typical C&O: It's pretty, with views of the Potomac, the canal at various water levels, and the occasional rock cut.
I walked a little past mile 19 to Pennyfield Lock, had lunch, and turned around. This is a section with no efficient alternative route back. There are lots of side trails that up the mileage considerably. I did change up the last mile and a half or so by taking the Berme Trail on the other side of the canal.
The hike was a little over seven miles each way, but with a few side trips to restrooms and the like, it came in at over 15 total.