I used to have one when I was younger where I was at the beach and was facing away from the water standing on the shore, it was a busy summer day with people sunning all around and kids playing and making noise. I'd then turn around and see a huge wall of water that went as far as I could see from left to right and a good 200/300 feet up in the air just roaring towards us.
I'd start to run but then realize that no matter how hard I ran there'd be zero chance of getting away from it and would just turn and face my fate, then it'd slam into me and I'd be getting tossed and turned all around and upside down and then after some struggle I'd make it to the surface where I'd see dead bodies floating all around me and people from every direction screaming for help.
Then I'd wake up. It was one of the most real and vivid dreams I ever have had and I'd have it all the time.
I had same dream dozens of times over years while I was younger but haven't had it for probably 10 years now.
I think it all started after I went to the beach with my boogie board when I was younger, before a hurricane hit us (was living down in South East FL at the time) and decided to catch some of the unusually large waves, I guess they were bigger than I realized from the shore and when I got out there I was getting pulled out by a under tow, the waves were bigger than I had ever swam in at that time as well and one of them caught me, raised me up into the air (what seemed very high at the time) and then slammed me down into the ocean floor, I hit on the back of my neck/upper back area and it forced the air out of me and I ended up swallowing a bunch of salt water.
I thought for a mew split moments that I was going to die, but found my boogie board (which was tethered to my leg) and pulled my way to the surface and swam back to shore.