More battery info than you ever wanted to know.....
http://jgdarden.com/batteryfaq/batbrand.htm

Interesting.

I had a horrible time with the Blue Optimas in 3 boats...and it was early 2000's. Never had problems with other batteries till then, and never had since getting rid of them...

I just replaced my blue top Optimas that were in the boat for 10+ years. Only replaced them because they just got weak enough that when I would start the boat, it would shut off the GPS. No problems otherwise, just more of a nuisance. I have 2 blue tops in there now no problems. The boat sits for months at a time, turn the battery switch on, and it fires right up. I actually never put a charger on the blue tops now that I think about it.

And yes, all AGM batteries like Optimas like to be trickle charged. Throw 10 amps at it like a normal battery and they'll die.

I know that not everyone will believe this but it's 100% true. I installed the blue top Optima’s in my boat in 2005 and they still working perfectly. I charge them once a month in the winter and turn battery switches off when the boat is not in use. Knock on wood, but I have never had any trouble with them. They are the Original Optima battery company not Interstate like they are now.

August of 2000 is when Johnson Controls acquired Gylling Optima and moved production to Mexico . . . .

Highly Recommend the Exide Edge Marine AGM. Packs a serious punch, better then Optima Blue Tops, plus they are very inexpensive for a Marine AGM.

I too had issues with Optima's lasting, seems like if they get too deeply discharged, they never come back fully, even with CTEK/RECOND charge.

I was shopping for batteries to hold up to a large stereo system, and provide good play time. The Exides provide tons of current to keep up with the demands of the stereo and have long discharge times.

the last set i had did just that in very short time to, once it started to slip there was no coming back. A few people suggested i was not charging it properly or not this or that with whatever charger was on my boat but truth be told . . . . i really dont wanna put that much thought into making a mediocre product survive let alone one i had lost most of my faith in anyway.

I have Exides Nautilus Dual's in my motorhome and that thing sits for months on end and never an issue, put key in and she rolls right over like i just parked it yesterday. I will probably put Exides in my boat as well, mostly because they have a bigger service and sales network then Deka but also because they seem to have a pretty strong following here . . . .

Never gotten less than 10 years from my Interstate/DieHards, but I am in the North where batteries last longer. Keep them fully charged and cool off seasons and they last and last. Had at least 7 last over 10 years.

Johnson Controls handles the Napa batteries West of the Mississippi and Deka/East Penn handles everything East of the Mississippi. The Napa marine batteries are pretty good for the money, they are same as Deka east of the river.

You can get Deka at Napa locally