Lighthouse Marina & Resort is on the Mokelumne river in Isleton. This is the first place we went to try out our kayaks on the delta. We're avid campers and this was perfect for a weekend getaway in the fall. The campground is very nice and the launch is right across the road. We didn't cover a large distance but we had fun exploring Willow Berm Harbor and just paddling around. This is also where I learned it's best to check the tide table before going on a serious paddle. I learned the hard way it's not as fun to paddle upriver at low tide.
This is where I also learned not to put a non waterproof camera in your pocket. I dropped my camera near the ramp in about 4 feet of water and was unable to find it right away. After paddling for an hour we returned to the ramp and I was able to recover the camera. I put it in a bag of rice for a little over a month and unbelievably it still works! Now I only take my GoPro with a float attached so I have no worries.
If you camp at Lighthouse there is no fee to launch your boat but if you decide to come for the day it's $10 to use their boat ramp. There are lots of other marinas nearby but I don't know what they charge to launch. I look forward to returning to this spot and doing a bit more exploring.