Beach resort in Karnataka/Maharastra/Kerala

I will visit India in Feb and I will have a week vacation together with my daughter, granddaughter and son. We will be a few days in Mumbai but then the plan is to head off for some beach place for the rest of the week. I have something against Goa (too western, may be wrong) so trying to find something else. As we have only about five days would not like to spend too much on travel. Have been looking at Kerala (eg Varkala beach area), Karnataka (Karwar or Mangalore), Alibag (Maharastra) could be an option but was there last year.

Karnataka would be a good option as we could go there by train (an experience for us). Varkala looked nice but first flights to Trivandrum and then quite a long drive.

We are mostly looking for a clean beach, relaxed environment, quite close to a train station/airport. Any good hints?

Beach resort in Karnataka/Maharastra/Kerala