I didnít check other manufacturers but Blue Seas only has 12 volt outlets up to 15 amp that I found on their website. I have never seen a 30 amp one. And you would also have to find a plug that would carry 30 amps. Why not install the small inverter next to the main power panel and just use an extension cord to run out to the cockpit? Much easier to do and then you can use a circuit breaker on the main panel to power it.
If you are one there is no explanation necessary.
If you arenít one, there is no explanation possible.