Ridge Vent Question

I live in deep south, coast region where it gets hot and humid. I just had a kynar 500 metal roof put on a hipped roof that is 3:12 slope. The previous shingle roof had a ridge vent. They used a sharkskin like underlayment which covers the gap where my old ridge vents were. The contractor said I didn't need ridge vents because my attic is so small and the metal will keep the attic cool. I have soffit vents. Will the soffits let humid air in that can't escape? Seems like a bad idea to me. I've done some research online but I can't really find much that says it's ok to do not have ridge vents.

+1 Unfortunately, this is another example of a contractor who is probably a good roofer that does not understand some ventilation fundamentals. Needs to be vented if it was vented before (at least through the ridge).