Caged at the beach / tips for lying flat

Hi there! I’ve had my cage on and off for quite a while now, but today marked the first time I went to the beach with it locked. Overall things were fine and my bulge wasn’t too noticeable. The only hiccup was some soreness when lying prone to tan. Part of this might be because of my current cage size (I plan to downsize once I can afford it), but does anyone have tips for comfortable stomach-laying while caged? Since I visit the beach regularly, I don’t want this to turn into a bigger headache.