The entry requirements haven't changed in at least as long as I've been paddling.
A Level3 is neither required nor adequate for entry.
The stated creteria are that you must have either:
1. Completed the Liffey Descent since 2007
or
2. Completed three rough-water marathon races this season.
or
3. Get a level3 instructor to sign your form, stating that you are of the required standard to complete the race. this isn't the same as getting a Level3, it's up to the instructor whether or not they agree and you shouldn't feel bad if they say no.
A rough water race is a marathon race that's on not completely flat water.
There are three left before the Liffey Descent:
Erne river race, the Lower Liffey race and the Corrib race - dates in the stickie list.