Cranking battery question

It's time for me to replace my cranking battery. Without getting into a brand debate, I need to know about the CCA/MA. I have the Mercruiser 350 mag which lists a minimum of 550/700. The last one I bought was an 800/1,000. My question is whether the 800/1,000 is overkill for the money or the more amps the better? What amps are you guys running compared to what the engine calls for?

Anyone?

I run an optima 34 series blue top.

I just put my battery tester on it and it showing 850 CCA.

IMO nothing is overkill when it comes to a battery. The extra amps will not hurt your boat by any means.

I have a large battery bank for the stereo that can be switched over to "jump" the starting battery so I use the smallest red top starting battery they make. It's a petty small battery probably below the rating but has worked without needing a jump for 3 years. Even fires the boat after sitting for months without being charged. Of course my boat is FI and fires right up. After sitting for a few months it does turn over a little slow but still fires up.

You shouldn't really need that many CCA's to start a boat. How often are you actually starting the boat at freezing. You should be fine with anything in the 500+ range. In my opinion optimas are way overpriced. They are good batteries but you can get a better Deka AGM for less money. If you don't care about having an AGM battery look into the Deka DP24 or their true starting battery the 24M7. They are good batteries and should be less then $100. Sorry about the brand thing. A CCA rating really isn't enough to really go on. The Deka's we have consitently test better then the listed specs. They are also made in the US.