Purchasing a Boat; advice

As a general rule Catamarans are more difficult and costly to find slips for due to their beam, and the further inland from the ICW you go the cheaper it gets. In some areas you may be able to find dockage behind a residence. However in many areas living aboard is prohibited. So you have some checking to do. I'd suggest deciding about where you'd like to be, getting a list of marinas in that area and making some calls to find rates and whether living aboard is permitted.
As for boat recommendations in the 45'-50' range there are just so many. Maybe you could narrow it down a bit to some boats you're attracted to. Also, since you intend to leave the boat in So. Fl. through hurricane season you'll want to check with insurance companies. As for your 50%-50% it should have little effect on your rate. Most marinas retain the right to rent vacated slips to transients, but you reap no benefit.

I've often wondered why most marinas in FL don't allow live aboards. Any thoughts?

It's not just Florida.

1) Pollution
2) Zoning regs.
3) Taxes
4) Competes with hotels and vacation rentals
5) Imagine you buy a nice waterfront home only to find your neighbor has a virtual hotel at his dock or a bunch of live aboard boats anchor off your bulkhead for the season.
6) People looking to live on the cheap often buy vessels on their last days of life to live on then walk away when they get too bad.
7) Strain on municipal services.

For starts Gray water. But back in the day when regs for live a board and transient anchoring started it was not unusual for boats to just pump out where they were. Yes pollution was a reason. Thankfully people are more responsible today and there's more pump out options. In a marina I ran we had a couple on a old Bayliner who used to pump out at night rather than tip the town guy $5. Knew it, but couldn't prove it. Marina contracts may require insurance, but I've yet to see it verified. I know one marina up here with several derelict house barges that's a prime example, and I can remember many old boats abandoned at marinas. Some people think living on a boat can be life on the cheap. Then they find out why you don't want to be a boat's last owner and walk away.

What are you looking for in a boat? How many staterooms? Are you looking for a sportfish or motoryacht? Flybridge or express? Needs, wants, uses. You have to be more specific.

With that kind of budget, I think I'd be looking at Viking, Hatteras, Hinckley, Sabre and a few other brands like that... (Alden, if they're still around, etc.)... In our case, I'd just run right down to the Sabre store, order a 54' flybridge, call it good. Er... if we had that kind of budget.

But much more would depend on how you intend to use the boat, what kind of space you need, etc. Can't do much guessing without knowing more about that.

Friends keep their liveaboard home base in Jacksonville, then go back and forth to Bahamas from there as hurricane seasons allow.

-Chris

One additional question for the OP, you mention Caribbean cruising but then you go on just to talk about Bimini and the Bahamas. There's a huge difference in the boat required to cruise in the Caribbean versus the Bahamas.

Are you happy going slow or need moderate speed or more?

You ask about the "most cost effective marina". What?

I agree. IN the 45-50' size range, if someone wants to cruise the Carribbean, the only thing I would recommend is a stout SF. In that size you need the fuel range and seakeeping abilities that only a SF can provide, unless you go larger. Or possibly something like a 44' Lagoon power cat, but then get into the dockage issues. If only doing the Bahamas then a motoryacht would be fine.

Royal Palm Marina or City of Dania marina would be good budget priced marinas.

Sport Fish. I think most boats are going galley up or mid-level these days to make it more a part of the entertainment area. The galley aft is pretty new. Personally I don't like it. It splits the lounge/ aft deck entertainment area.

Thank you , NYCAP123. would a Sportfish be a good live aboard?

Reading comprehension issues again? I am dead serious. I am sure you are thinking EVERYONE in the world wants to cruise around, rolling around in a 7 knot tub or trawler taking years to travel a distance other boats can do in weeks. The problem is, you cannot think about how people enjoy yachting, all you see on your horizon is trawler, trawler, trawler. But most people don't want to be stuck at the helm for days at a time, aren't on retired time with no homes and no lives and no family members they need to visit, and traveling at 7-8 knots to save a dime, while pissing away thousands isn't on most people's agenda's. And, with a SF or motoryacht you have the ability to cruise around at 7-8 knots and get the same fuel economy, Sportfish do it all of the time, but at least they're catching dinner in the process! Nor is camping on the water, most people's ideas of yachting.

BUT, if you read the OP's post, he said he wants to "easily cruise to Bimini and the Bahamas. Wants to cruise 3 months at a time to/in/and from the Carribbean with Florida as his base." For that you need speed and range. The OP doesn't sound like he wants to spend 10+ hours in a 45-50' trawler just to go from Ft. Lauderdale to Bimini (50NM) when he can do it in less than 2 hours. It would take the OP 3 months just to get down and back to St. Maarten from Ft. Lauderdale in a displacement hulled 45'-50' trawler. I'd recommend a Lagoon 43/44'" power cat with the large engines, as it has the range and will cruise at 16-17 knots and is a great seaboat, but he doesn't want a cat. Plus gets 3 nmpg at 10 knots and 2 nmpg at 12 knots. Motoryachts, don't have the fuel range in that size, and quite frankly I can't think of a 45-50' motoryacht designed for that type of trip, most open ocean, the Mona Passage, 180-185NM legs without any fuel. Also doing overnighters in that area REALLY sucks, always rougher at night. Meanwhile something like a Hatteras 45' GTX could do that with ease based on all aspects at it's 35 knot cruise, but wouldn't be my choice due to the liveaboard situation, but a 50' or 53' Post would be excellent as well as some vikings, Hatteras or others.

WHAT WOULD YOU RECOMMEND??????

In the 45-50' range? Able to have a 185NM with 20% reserve? At least a 20 knot cruise so that you can make it from Long Island to Turks and Caicos, or Turks and Caicos to Puerta Plata in daylight hours without having to do an overnight? Which models exactly? I've never found SF to sit badly on anchor unless you have a tower and/or it's a Bertram (with a super deep v and a bunch of chines to slap).