My wife Mary is the First Mate of the trawler, the Patricia Ann. I jokingly call her the Admiral because any decision by me, the Captain, can be overruled by her but we are usually a good team and in agreement.
A yacht is a small city afloat. There are at least two power generation systems, both alternating and direct currents and maybe a wind and solar system on some boats, a waste treatment system, hotel accommodations to allow the crew to sleep and rest, food preparation systems (electrical or propane), food storage systems (freezers and refrigeration), water systems to allow for bathing and cooking, navigational systems to allow the yacht to move about and even entertainment systems with movies and concerts.