Dw conditions requirements

hi everyone, how is depth related to the size and quality of bumps for dw. I have been struggling to find conditions for sup dw. the last time I went, there were about 20 knots and 1.4m swell, I was about 300m out at sea and there were no bumps, just onshore swell. i have a friend who said it’s related to depth. he says it’s too deep. what are your thoughts?