Parallel.
Pros-- shaded panels don't stop other panels from producing. Voltages don't add, so if your Mmpt solar charge controller has a limited input voltage range, say 12 to 50v, and panels are say 20v, you can run them.
cons-- have to fuse each panel usually. Amps add together, may exceed your SCC amperage limit. Higher amps means larger wires. Wire connectors have amp limits, the common mc4 connectors may be exceeded. May not oroduce power early and late in day, as voltage may not be enough to trigger the SCC. Voltage losses more on low voltage, high amps
Series.
Pro and con the ecact reverse of above.
Pro-- higher voltage, less amps, may let you fit more watts into the specs of your SCC. Smaller cables. Connectors may not be exceeded. One fuse for whole string. Voltages add so may allow charging earlier and later in day. Less voltage loss. More efficient for SCC to operate at higher voltages usually.
Con-- added voltages, plus their cold temperature correction, may exceed the allowed input of your SCC.
In general, series is best if able. parallel for shading issues, or series panels exceed scc voltage inputs.
Oh, also on a boat, some folks like to keep voltages below certain levels for safety, I believe.
