Queensland draws the line at engine power, not boat size. You need a marine licence for any boat with an engine over 4.5 kilowatts, roughly 6 horsepower. Read that as 'more than 4.5', not '4.5 or more', because the regulator writes the rule in kilowatts and the difference matters right at the boundary.
There is a way around it, and it is worth knowing before you book. You can operate without a licence if someone holding a valid marine licence is aboard and able to take immediate control. That exemption ends the moment you tow anyone, on skis or on a tube, which requires a licence no matter who is with you. So the honest answer depends on how you want to use the boat. Only ever going out with a licensed mate? You do not need one. Want to head out alone, or pull the kids around behind the boat? You do.
The upside is that this is a one-off. A Queensland marine licence never needs renewing. It is valid for life.
The rule you get assessed against is the rule that governs the water you train on. One of the mandated practical competencies is operating at 6 knots or less, and the Sunshine Coast waterways used for training sit in and around gazetted 6-knot zones. Pumicestone Passage, the Maroochy and the Noosa River all carry them. These are current rather than historical: the Pumicestone Passage 6-knot zone took effect on 9 January 2026. The exact boundaries are set by coordinates, so check the Maritime Safety Queensland map rather than guessing at a ramp. So the 6-knot competency is not an abstract regulation on this coast. It is the water the course runs in and around.
The other thing worth asking any provider about is group size, because helm time is the product. Maritime Safety Queensland sets minimum practical training and assessment times that scale with the group: 105 minutes for one student, 145 for two, 185 for three, 225 for four, and each extra student adds at least 40 minutes. Forty minutes is a floor, not a target, and the regulator's own breakdown notes that most students will require multiple practice attempts. Australian Boating College aims for 45 to 60 minutes at the helm per person across roughly 3 hours of practical training, which sits above that floor when groups stay small. Ask what the group size will be on your date, here or anywhere else. Two courses can take a similar day out of your life and produce very different drivers.
Training runs on a 4 metre Quintrex side-console tinny. The regulator requires the training vessel to be commercially certified to at least class 2E and to give the trainer and students sun protection in their normal seating positions, and requires shade, seating, drinking water and toilets for students on the day. For a full day outdoors on the Sunshine Coast in summer, that is not a small detail.