Wow, you have gone so far!

First of all, you can go to Thailand by boat from Penang. If you want to go to Indonesia, it is too far. To go to Indonesia, you should take a boat from Malacca. Johor Bahru is at least 300 kilometers away from Malacca. Johor Bahru is very far away. Singapore is right next to Johor Bahru, so Johor Bahru is not near the Strait of Malacca. Malacca

Seremban Muar waiting near the Strait of Malacca