adding a rudder

Has anyone created a removable rudder for lake paddling? I’m looking at doing a trip to Lapland with some big lakes to cross and without a rudder of some kind I see it being a very frustrating journey with all that side-to-side motion.

Do you mean rudder or skeg? There are plenty of people who have installed removable skegs on their packrafts - there are even commercially available kits you can buy online ( Anfibio one for example: https://www.packrafting-store.de/Accessories/Anfibio-Skeg::691.html ).

There is plenty of discussion on this forum regarding this, for example:

http://packrafting.org/forums/viewtopic.php?t=665
http://packrafting.org/forums/viewtopic.php?t=571

I have skegs fittings on two of my packrafts but i rarely use them. They don’t add that much more tracking to be worth the extra fiddling when setting up the boat