This device only having the 3 pool length options was a development choice and the custom option was included in the manual in error (I will submit a request that we update the manual). I recommend you visit Garmin Ideas to submit the custom length as an idea. I would make sure to include not just the "what" but the "why"
Thank you. Given that I bought the watch because I read in the manual that it could put in custom laps, this is sort of a big deal. They definitely should update the manual, at the very least.
