As DazTheSlug says, it is pretty easy to police, the High Peak Marathon among others require that you put any GPS device in a sealed bag. If the bag is opened before the end of the race you are DQ'd. The problem is that GPS enabled watches are little different in appearance to standard watches these days so it's hard to tell at a glance if someone is wearing one. If a race is marked as "Navigation experience required" then it's up to each individual to step up to the mark not drag things down to their level.

Having an idea of where you are in relation to features on the landscape is part of fell craft, you don't get that from being a dot on a screen (of any size). If the ordure hits the air distribution device then you need to know or figure out escape routes *from your current position*

It does come down to honesty/personal integrity as well.

<BGClub hat on>There is no practical way we, as a club, can police what individual contenders use during their attempt nor would we wish to. Again it comes down to honesty and integrity. The round for the most part follows existing paths, do you really need to follow a dot on a screen for that? There's a few sections, such as locating the ramps on Bowfell, that are BGR specific but that's what reccies are for.</BGClub hat off>

For most races there's little micro-navigation required, it's more a case of follow a path/line to a feature then turn one way or the other. Why use someone else's favoured "short-cut"? It might not suite you and if you don't know it well enough and how it relates to the general race route it's going to cost you time.