Thank you!!
A full recap of the marathon is in the endurance thread in the training forum. Here's the session, and I did indeed end with a full-out sprint -
https://log.concept2.com/profile/1558013/log/68739755
Kirsten Kline has rowed a much stronger 5k than mine since I set that PR, taking the place of fastest 5k. She is a beast - so impressive.
The 5k was the second in the Ergon Metron Virtual Race series. I learned about it on the C2 site. There was a Summer Sweater 1k in July, and then the recent Ghost Rider's Revenge 5k. The series finishes out with a Frozen Hell No! 9k in January and then an Only Fools Do 2k in April. I registered for the full series because you get a pretty sweet-looking orange hat if you complete them all.
I second-guessed my pacing strategy pretty heavily going into the 5k, and ended up holding back from what some 5x1500 and 4x2000 pieces seemed to predict, with the hope of picking it up in the second half. I wasn't able to pick it up. It was late afternoon and I usually train in the morning (which is something that I need to get better at dealing with). The organizers were having some issues getting everyone into the heat and it started about 15 minutes late, and I was trying to stay warm and loose for that time, without burning energy too quickly. I feel grateful that we were able to race virtually, and I know that things happen. But I don't think I had more in me that day. The race felt very fast from the start and it was a mental struggle to stay in it. I was able to pick it up from an average 1:48.5 to 1:47.9 for the last 500m - compare that to the full marathon ending!