I took my non diving girlfriend to Mimpi Menjangan on our second trip to Bali. After 2 days of snorkeling around Menjangan Island she told me she wanted to get certified. We had an instructor there the next morning, extended our stay and she got her certification. You never know. It sure surprised me. It was a great place to get certified, and really nice diving. There isn't anything much else to do up there, but it is a beautiful spot. We moved from there to Tulamben, which has a lot to offer (diving). I would recommend Scuba Seraya over the Mimpi Tulamben. Sanur and Ubud are great for hotels and Bali culture but a long haul for dive destinations. Incidentally my girlfriend (now wife) has 150 dives and has become an excellent dive partner. We just returned from Raja Ampat.