I guess Coral Queen is the Govt. ferry that takes you and I've heard it's a great experience. You should find more details on their website. Other ferry service include Makruzz and Sea Link. Hope it helps!
The govt ferry is safe but pretty basic, non-AC, simple seating, and the boarding can feel a bit chaotic. It’s fine if you're on a budget, but not the most comfortable option. There’s also no proper online booking, so you have to buy tickets at the STAR counter a couple of days before, which makes planning tricky. I recently experience Go Nautika and I really had a best premium experience. It was value for the money I paid so no complaints.