Surfing Waves

I surf a 7"3 bic mini mal and to be honest I think its an arse of a board as I find myself running up and down it to get proper positioning.
Any tips for this or would a shorter board be better as my back foot would be constantly planted and I could distribute my weight easier to do some turns?
(Was thinking of a 6"9 Westbay Slayer)

I have a six ten fatboy flyer very easy to perform manovers on but so is my 7,6 practise practise