Afraid its a no on the Venture, about the best you can do is set waypoints and points of interest by connecting it to a computer. That will need a cable, on my old one it was a serial cable. If you want to have a go at OS maps on a GPS device, beg / borrow and used smartphone and try the 7 day OS maps trial. You do not need a simcard in the phone, use wifi at home, and save maps to the phone. If you like it you can add a battery pack to extend its life and look at putting it in a waterproof case. I use this setup in the kayak and walking. And yes I do carry a map and compass, or even the old etrex as a backup. Other good thing about the OS app is that when you subscribe you can print maps out yourself.