Divers looking for treasure are sucked into a vortex, emerge in a peaceful city hidden under the ocean. Museum of stuff found in ocean (e.g., '67 Corvette car). Spoilers?

[Lucinda]

Divers looking for treasure are sucked into a vortex and find themselves in a city under the ocean. They have no war and are peaceful. They have a museum full of stuff that has wound up in the ocean witha '67 corvette in front of it. They kill someone and are banished back in time 300 years. They meet a man who wants to know if they're from YALE because the talk funny

[Rainbowheart]

Anything on the Underwater Cities list?

[beichst]

I believe you are seeking:

Robin Cook Abduction

[Kris]

Google Books preview of Abduction by Robin Cook - Brad's suggestion:

https://books.google.com/books/about/... There are different cover images.

[UPDATED]
Quote from the book:
- "While Suzanne and Arak continued to discuss sonar and its threat to Interterran security, Perry wandered the full width of the World War II gallery. Some of the paraphernalia seemed in pristine condition, other objects were barnacle-encrusted like the Corvette outside the museum."
- "They don't act like enemies. They're so gracious and peaceful. It's hard to imagine them doing anything unkind to anybody."

[Kris]

Lucinda, what's the genre (which we need to add to the header/ topic title) - e.g., adult fantasy thriller, mystery, etc.?

I copied plot details to the header. Feel free to edit it.