Charter boats are barely profitable in the best of times. Miami is a unique market, it's not a fishing destination, more of a tourist (I sure don't know why) and business/convention destination. Most of the charter boats are based out of the large hotels and cater to conventioneers and business clients, running 4-6 hour trips and trolling for dolphin, wahoo and billfish. Nobody expects to catch much and the corporations foot the bill. The majority of the boats are privately owned and leased to the hotels or charter companies. The owner gets a small income and large tax writeoffs. The captains get a salary and the mates work for tips. I ran a charter boat for a year out of the Ft. Lauderdale Marriott. It was much more like babysitting tourists than it was fishing.Never would have thought there wouldn't be enough charter boats in Florida, could this still be a profitable business in Miami ?
The price of dockage, housing and costs of living in the Miami area would be prohibitive to try to establish a charter business, unless you have some good contacts.
The real fishing destinations, where people travel with the intentions of catching fish and bringing some meat home, focus on bottom fishing, snapper, grouper, amberjack. The boats are mostly owner operated with a much tighter budget than the Miami Diplomat, and without the captive audience. If they can't produce fish people won't come. With snapper and amberjack now both closed in the gulf, and the grouper limits so tight, who's going to spend $1,000 to catch 3 fish?