Live crew tracking for ultras
Send them out,
bring them home.
SendOff is race-day crew coordination for ultramarathon runners. Your crew works one board at the aid station, and everyone back home watches the splits land live.
Watching needs no account and no app. Anyone with the link can follow along, and every public race stays readable forever.
What your crew sees
One board at the aid station, one page for everyone else
The crew view
Crewing an ultra is hours of waiting and then a few minutes where everything happens. While they are in front of you, you tend to the racer: check them in, send them off. That is all the board asks of you while your hands are full. Fluids, food and notes go in afterwards, once they are back out on course. It keeps working with no signal and sends what you logged when you have bars again.
The race plan
The course laid out leg by leg, the cutoffs you are racing, and the day so far in one page: splits, pace against the cutoff, time in the pit against time on course, elevation. Send the link and family and friends follow it live, updating as your crew logs it, with nothing to install and no account to make.
How it works
Three things, and one of them is race day
- Set up the race
Lay out the course leg by leg, add your racers, set the cutoffs. Done in the week before, not in a parking lot at dawn.
- Work the pit board
Check them in when they arrive, send them off when they leave. The detail can wait until they are gone.
- Send the link
Everyone who could not be there watches the same splits you are logging, as you log them.
Who built it
It started on a plane to Vermont
I was on a plane headed to the Blood Root Ultra in Vermont to crew for two buddies of mine and wanted to keep track of their lap times and projected finish. I started with the idea of doing so in Excel. The idea snowballed into creating an app with not only a projected finish, but a map showing their projected location, a place for me to log their intake after every lap, and visible to the public so their family and friends could follow along at home. By the time the race started, I had a fully functional app built in GitHub. When they arrived, I checked them in. When they left, I checked them out. During the down time I continued to develop and add new features to the app. By the time they finished, I had charts and graphs and a full breakdown of their race to export for them.
As a crew member, the tracking of their location and fueling took out all of the guess work and let me focus on what really mattered in the moment, when they were in the pit. I knew I wanted the same tool for my own upcoming 100 miler. I DNF'd Sangre de Cristo 100 in 2025 when I ran without a crew and relied on my own judgment. I gave up when I didn't think I had time to hit a cutoff, when truthfully, I probably had the time. I wanted the competitive edge coming back in 2026 to finish that race strong, leaving bad decisions out of the equation.
I also thought, how many other people could use this tool for the same reason, or simply to help their friends and family follow along with their race? So I developed the app into a platform where anyone could set up their own race and pass out the link. They can invite their crew to check in and out and keep up with fueling and notes, or they can use the simpler racer page to run it themselves if they either don't have a crew or they're at an aid station that crew doesn't have access to.
My hope is that this tool helps people reach their goals and easily be able to share that journey with those they love and care about.
Jason Dupree · September 2026
Beta access
Ask for an invite
Beta SendOff is new, and it is being built while it is being used. It has run real races and the crew work is solid, but things move week to week and you will find rough edges. Running a race of your own is invite only while that is true. Watching one never is.
One thing worth knowing before you put a race in: a race marked unlisted is not sealed. It stays off the public list and out of search, but the files behind it are still served from a public host. Sealing that is the next piece of work. What is stored, and who can see it.