I see from posts that there are still people using the Toggle lock on their GPS's when using in a waterproof bag.

I think there is a much better way. It is not a new idea and was shown to me by Tom Chalko, but here it is again for those who missed it.

Find a piece of nylon tube that is roughly 10.5mm OD and 6.5mm ID. Slice a 2.5mm - 3mm section off it with a Stanley knife or similar (careful of your fingers!) It needs to stand flush with the top of the toggle. A bit of trial and error will get it just right.

Push the 'ring' over the toggle, (it should fit snugly) and you have a toggle that can't be accidentally pressed by the pressure of the bag, but can be pressed through the bag and manipulated easily when you want to.

A simple and very effective system that we have been using successfully for quite a few years.

Carry a handful of spare 'rings' in a plastic zip lock bag and hand them out to your friends!