Your probably OK, read the section here on "when do panels require regulation"
http://www.westmarine.com/webapp/wcs/st ... panels.htm
I dont understand why you want a solar trickle charger however. When you are using the boat in the summer, it likely wont supply the power you need (you have to do a current consumption budget to see what you need similar to the example I gave) and in the winter, if your battery is in the garage, you will need to maintain the charge with some other method..
One other somewhat messy subject with batteries regardless of how they are charged.. You normally dont want to let the charge of a deep cycle battery go below about 50%. So in my case of having 230 amp hours, I have 115 amp hours to use - gives me some reserve over my normal use. On occasion (like a 4 day trip Im planning), I may let the batteries go below this as they are cheap batteries and in the overall "cost" scheme of things, occasionally drawing them down below 50% is not going to matter. But you probably would not want to do this on a regular basis (I say probaby because it may be cheaper to wear batteries out faster by doing deep discharging than to buy all the stuff to keep them charged above 50%). The cheapest way to monitor battery charge is by measuring the voltage but this also has all sorts of inacuracies - but I think its adequate in the overall scheme of things. So you may also have to consider some way to monitor the voltage of your batteries.