Heart Rate Monitors and GPS in CTRs, endurance- are they allowed?

So basically what the title says.
I’ve found in ECTRA’s rules that heart rate monitors are allowed but must be turned off prior to P&R, but I can’t find anything about GPS. Does prior to P&R mean before you pass the timer or just before you enter the P&R area?

I’ve been all through AERC’s rule book and can’t find anything about either.

I don’t think the AERC has any issues with either of them, as many riders ride the whole ride with them, as well as checking pulse before P&R. At my last endurance ride I saw a few of the top finishers crew were helping them with hand-held monitors before they went to P&R, that way you know the horse is down and can present straightaway. I’d love a crew like that! I personally don’t use a heart monitor, but do use GPS, mainly just to track progress on training rides. I turn it on for endurance rides but never really look at it.

Yes both are allowed in AERC.

I have ridden in both AERC and ECTRA events with both and never had an issue. With the ECTRA rides, tack needed to be removed before P&R and vetting for each check, and since my heartrate monitor is attached to my saddle, it was never an issue. Have done plenty of tack-on checks at AERC rides and heartrate monitor has never been a problem. My GPS stays on my wrist the whole time though and nobody from either organization has ever said a thing about it.