I can assure you that there will be significant issues. I have lived here for 30 years and presently live on a salt water sailboat access canal and have a 30 foot Cape Dory cutter a few feet outside my back door. Now, with that said I also ran my own marine business along with my photography and lab pursuits since living here in Florida.
First of all, to obtain the space on board that you would need, in a specific boat, within the size range you mentioned, you pretty much would be limited to a center cockpit design to provide you the necessary space a small darkroom would require. In fact, you could probably combine a work area that would convert into a darkroom in the passageway between the main cabin and aft cabin. Another option is that you could also utilize one of the head compartments and you could do it in such a way to make the head area convertible in nature, easily changed from head to darkroom. Some custom mods would be obviously be required. Any space you would use should be as close to the center of the hull as possible fore and aft. This is why a passage way in a center cockpit design would be a good choice, especially if a head compartment is nearby so that you could use the sink if it is plumbed to contain the chems you would be using. Of course you could always add a sink set up in the passageway area if you wanted. You could always use the forecabin as your primary cabin and use the aft stateroom as your lab, but that is being really devoted!
The space issue is just the tip of the iceberg you would be dealing with. Your greatest problem would be dealing with chemistry. Any sinks or drain basins you would use would absolutely have to be plumbed directly to a special gray water tank just for containment of the chems, not a typical waste tank. The chemical gray water tank would have to be designed to be easily removed from the boat as you would not be able to use a standard pump out facility and you certainly can't discharge any photo chemicals overboard. Safe storage of the corrosive chems is another factor. Aside from the chemical issue you really don't have any other huge issues to contend with except for humidity and mold (actually those are quite huge issues down here). You will also have to deal with condensation inside the boat during the winter months (nothing fresh movement of air can't resolve). The summers will be a real challenge for you. In a cruising boat of the size you are talking about you are going to have to run two central A/C units for certain, especially for liveaboard. You will die in there otherwise. Those units will have to run 24/7. However, some people run minimal A/C but that just causes all sorts of issues like mold growth inside lockers, cabinets and other closed off areas. My personal opinion is that mold is going to cause you all kinds of grief based on my experience in the marine field. Even with A/C, some components on an enlarger will rust unless you always keep up real good anti-corrosive maintenance practices. Keep in mind, the photo aspect is only a very small part of what you will have to deal with. The maintenance on a 40+ footer down here is huge. Don't think for a minute this is easy street down here. The climate is extremely brutal on everything. Your boat will take up all of your time to keep it properly maintained, it is a constant battle and you will always lose. Unless you are a millionaire or better, do not think for half a second this is paradise, or even close to it. Don't listen to the hype or be fooled by all the pretty pictures. It is not as blissful as people think, warm yes, blissful no. The first year on your boat will seem fabulous, then the reality will start to rear it's ugly head little by little, when one day you start to notice your halyards are turning kind of gray, the canvas is starting to look dingy, the GPS antenna is turning yellow, the teak is developing black spots, the bugs are getting into everything and making a mess, the maintenance products are leaking from their containers, things are starting to rust, plastic is starting to deteriorate, blah, blah, blah. ...... You get the idea. It's great in the beginning, but it doesn't last unless you wish to be a slave in labor and money. Anything down here takes a huge beating from the environment, cars, boats, buildings, anything outside and out of an air conditioned environment. Even in my house, with a superb A/C system that controls humidity levels, I keep equipment like lenses that I am not using sealed inside zip loc bags just to be on the safe side. I keep much of my equipment is sealed cases that are gasketed. It's worrisome enough to prevent equipment from humidity damage in a building here. On a boat, you have increased that challenge a hundred fold. The bottom line is you have a nice dream and it would be great to have the situation you desire but reality has different plans for you, that I can assure you of. Like I said, if you have tons of money and tons of time then you might be able to pull it off. But, your headaches of maintenance and deteriorated equipment and property will never end, guaranteed! The other problem you are going to have is trying to find a liveaboard location, they have all but disappeared with the rampant development of marinas and such into waterfront condo complexes. If you plan to cruise, take images and process them on board, you will discover there is very limited mooring times in community basins, most just don't allow stay overs for very long and liveaboards are pretty much out of the question in a mooring field. Today's Florida is nothing like it was 20 years ago. Now, it is all about developments and selling a dream, a hyped one at that. Before you buy a boat and start customizing to make provision for any photo use I strongly advise you to come down here and charter a 40 footer for a few weeks and cruise the state, do it during a span when you will be here during the heat of summer and during hurricane season. That way you will have a real world experience of what to expect during summer tropical heat, storms, rains, lightning, and a potential tropical threat from a hurricane or smaller system. If you are just planning to be around during the winter months, then you need to determine where you would keep your boat in the off season, how it would be maintained, and how it would be protected during a storm threat. Marinas are few, boat yards are really disappearing, developers take them over and convert them. Just getting a large boat serviced or hauled can be a huge issue in many areas of the state except for metropolitan areas like Ft. Lauderdale/Miami, Tampa/St. Pete, other areas can be next to impossible unless you want the yards to do work for you. Also, think about insurance regarding the idea of having photo chemicals on board and the Coast Guard may have something to say about it as well if you get inspected. Grand idea you have, I admit in the past when I was naive about Florida, similar ideas crossed my mind over the years, but there are two sides to the coin, the fantasy and the reality. You can definitely do it, no question about that. Simply, it comes down to how badly do you want to do it and what price are you willing to pay in dollars, frustration and work, work, work. No joke here, I am very serious about what you will be faced with.
