From experience printing a bunch of different planters with varying settings and printers, without post-processing/sealing the answer is “not reliably”. You can increase your chances by using many perimeters and surface layers, high heat, and thicc extrusions, but you are still just stacking swiss cheese slices on top of each other hoping the holes don’t line up.

With ten days submerged, even the tiniest of defects means water can and will seep in.