Thanks to those who responded. I finally have the laptop with the u-blox card installed. It appears as:
umodem0 at uhub3 port 1 configuration 1 interface 0 "u-blox AG - www.u-blox.com u-blox GNSS receiver" rev 1.10/4.05 addr 4 umodem0: data interface 1, has CM over data, has no break umodem0: status change notification available ucom0 at umodem0: usb1.5.00001.1 It looks me a little bit to figure out how to use ldattach(8) but reading umodem(4), ucom(4), and then figuring out that ttyU0 and cuaU0 were the important interfaces was the key. # ldattach -s 4800 nmea /dev/cuaU0 With that added, I have a sensor for ntpd. $ ntpctl -s Sensors sensor wt gd st next poll offset correction nmea0 1 1 0 6s 15s -45.090ms 0.000ms Thanks for the pointers and feedback from everyone who responded. Bryan