After spending some surfing this neck of the woods about 10 years ago the solution is to drive 5 mins north to the open beach breaks of Anglet which typically have better banks and more swell.
Biarritz has a resort/casino right there on the boardwalk so its always going to be constipated.
Even better if the swell is up is to head south and enjoy the view from Miki Dora's bench seat watching the open swells bending and wrapping into Europe's answer to Sunset - Guethary.
Oh the memories . . . . .
HV