Your post just snuck in ahead of mine there. I noticed you wrote…Technically, that’s not exactly technically so!For those who want to approach this technically, if you knew what the dew point temperature inside your boat was at any time, and you could evenly drop the temperature of the air down (with any kind of cooling system) to just above that point, you would not see any moisture form inside your boat, and you would have the benefit of that temperature of "cooler" air available to make you feel better. However, that temperature difference is not always enough to make us feel better, and the dew point temperature changes relative to the outside air temp and the humidity, and trying to manage that is very very difficult because it would take determining the dew point over and over and over continuously in order to adjust the cooling system to be sure you don't drop the temperature too much. This is why air-conditioners were made to just make the air as cool as possible and just pipe the water away...because it's much easier to do.
It is the reduction in humidity that an air conditioner supplies that is a large part of what makes air conditioning comfortable to a living thing. It does this by increasing the rate of evaporation from the skin which is moist. It’s what is referred to when we talk about the “humidex”.
A person will be much more comfortable at a higher temperature when the humidity is low than they would be if the humidity is high.
During a high school trip to Spain in the summertime I experienced this first-hand. It was during a heat wave there and the streets of Madrid (which is a city in the middle of a dry desert) were crowded as most people were walking on the shady side of the street. Being from the Great Lakes Region (and thus used to swelteringly long hot humid summers) we were quite comfortable on the less-crowded sunny side of the Madrid street because of the dry heat.
Maintaining a “temperature-dew point spread” (that’s what you are referring to) is what you want to do if you want to prevent fog (or even precipitation) from forming in the air, but you want to really maximize, not minimize that spread to maximize comfort in an A/C scenario.
It might have some effect on the condensation on objects that are below ambient temperature, as you suggest, and, on a boat, the part of the hull that is in the water is often cooler than other surfaces, so condensation would happen there too if the temperature-dew point spread is not kept high enough.
Cheers! – Brian.
that holds ice as long as a yeti, but at 1/10th the cost, so building a highly insulated box is not an issue. Russ may have been joking about dry ice, but it will certainly help out your ice bottles. Here on the south Texas coast, the ice we buy is what I call "barely ice" as it starts melting before you can get it to your cooler. I'm assuming Florida store bought ice is equally NOT cold 
