Do powerboats have big engines

This depends on the size of the boat. The smaller type such as 12 foot row boats will usually have 7 hp outboard motors. Some of the larger boats up in the 20 to 30 feet have been known to run up to 4 outboard motors around 300 hp plus each. Above these boats in lengths you will find most of them run large diesel motors cummins, Caterpillar, detroit(mtu) and Volvo's. Some of these larger 2000 to 2200 hp motors power these luxury yachts. Hope this answered your question