Has anyone used a larger coil on the AT Gold?

I just picked up a Gold for some water hunting this season, and it has the 5x 8 coil. I'd like to get a larger coil to cover more ground when needed. Any recommendations on a bigger coil that you have used with good results? 9 x 12? 12 x 13? etc. Thanks

I have the Nel Tornado coil I use with my AT Gold. Balance sucks with the big coil. Noticeable depth increase and of course coverage. I'm really happy with it. Great coil.

I also use the NEL Tornado, mostly for relics. Hunt in all metal with iron audio on, great depth. Mark

Thanks Guys!