The Tangled ride is most likely going to be an intamin tow boat ride, the one Paris has been using. It works with a cable underneath the water that pulls the boats, so no height differences.
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Frozen was rumoured to use the Shanghai Pirates system. But the boats look identical to the one from Hong Kong. See the two maquettes presented at D23. The blue seats are for Hong Kong. We know from Hong Kong that it is an Intamin chute ride (Maelstorm, Its a small world, Pirates). See the third picture for the delivered boats to HK. In addition Pirates has a 5 seater boat opposite of the 4 here. Based on this it seems unlikely that Frozen will use the ride system from Shanghai.
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