Probably but Tinned wire is absolutely unnecessary, unless you sell wire..

Ok, I thought that the tinned wire helped keep the wire from corroding that happens with copper wire and salt water air.

I guess sealed connectors are not needed also? I have always used the type that seal but they are a lot more expensive, if I don't have to buy them on my current project I can save a bunch.

I used marine grade, its really not much more at all... in my case was like .20 differance

It's not all about the tinnin g, marine is STRANDED, thats a huge deal in a boat... you can run stranded house wire if you want but what you gonna case it in? greenfield? MC? lol

Connections of wire to wire should be soldered, then sealed with plastidip tool dip.

Wire to connector (ring, spade, male-female butt) shoal be non insulated crimp then solder then platidip. Another is liquid tape....same stuff. The important part is lack of exposure to air and moisture.

Copper stranded is a recipe for disaster.

Everything I just wrote is related to dc. Dc travels on the outside of the strand......so more strands, lower resistance (impedance higher)

1 20a gfi will feed an additional 9 on the load side. Ac uses the entire line, so solid is a much better decision. Always ground up....or opposite of what u see in your house. This is for safety. Only.

All the marine stuff is stranded that west marine had....

Just to be clear, I was kidding about non tinned and non sealed connections. I always solder and then use a sealing heat shrink (not the standard stuff), or the connectors that solder and seal when you heat them. Plastic dip is a good idea that would be a lot cheaper, never thought about that.

Why ground up for safety?

I hope most of the posts here were made in jest. At the very least it looks like the majority boat far from me so I don't have to worry whom I'm docked next to, then again maybe I still do. Just to be clear, never, ever use solid copper wire or tubing in a mobile application. The vibration with cause it to fracture. I have seen mild steel fracture like glass in high vibration environments.

Ground up so a metallic (conductive) object cannot fall directly onto the load and neutral....following the path of gravity...at say a partially plugged into device.....

If mounted horizontally, ground goes to the right as you look at it. This is so a connection between ground and neutral is your risk, not ground and line....