First, an hour is not enough to charge a mostly depleted battery. Four to five hours would be closer.
Second, the marine batteries are not true deep cycle batteries. They are actually a hybrid between starting batteries and deep cycle batteries. Their construction more closely resembles the starting batteries. If you want a true deep cycle battery, get a pair of 6 volt golf cart batteries and hook them in series. There are some 12 volt golf cart batteries, but they tend to be very expensive and very heavy.
Retired electronics engineer. Avid paddler & birder.
2011 Silverado 2500HD, diesel, 4x4,crew cab, 8' bed
Palomino Puma 253FBS (27' 5er) & '94 19' Class B