Tipping in Komodo is not required and there is no fixed rule about it. The crew will never pressure you or make you feel obligated. That said, tipping is a common way for guests to show appreciation because the teams on board work long days preparing meals, guiding hikes, keeping the boat clean, and helping you stay safe in the water.
Many travellers choose to leave a small tip at the end of the cruise, usually handed to the guide so it can be shared fairly among the crew. It is completely voluntary. If you had a great experience and want to say thank you, a tip is always appreciated. If not, no problem at all.