Johor Bahru is not known for long sandy beaches. But it does actually have a beach, see the photo. This is over near the Zon (duty free area) where the ferry is. Singapore is visible across the water. Swimming might not be the greatest idea, though I did see 2 people swimming once.
Johor Bahru beach (you see about the whole sandy beach in this photo)
You can also find some people selling fresh seafood along the walk. It actually is a nice walk along the water. If the city did a better job of featuring it, it is possible to make it into something really nice. I don’t see anything about the walk in Penang along Gurnsey drive that is any nicer.
But if you really want a beach Malaysia has plenty of great beaches. Langkawi is the best beach location I have been to yet.
Related: photos from Penang – Early Photo of Me on the East Coast of Malaysia – Tourist Activities in Kuala Lumpor
Besides , Langkawi . There are other beautiful beaches all around Penisular Malaysia. East Coast of Msia like Pulau Rendang , Cherating and Pulau Tioman ( which you can go there from Mersing , Johor.