All your chart and software updates can happen through ActiveCaptain so you shouldn't need to access the physical card very often if at all. That said, I do have the remote card reader because...nerd. To connect your VHF to your 2 MFDs you will need;
- 1 NMEA backbone cable
- 3 terminators
- 3...
You gotta wonder. Are there humans behind these AI Bots, or are they just running amok on the internet? We should track them down. I wonder if bot-murder is a thing.
I'd try spraying some silicon lube into the key cavity and then quickly moving the key in and out of the ignition 10 or so times. These switches can get gummed up at which point the springs aren't able to line up the tumblers.
If that doesn't work, you'll probably need to replace the ignition...
Sounds like you are off to a great start. Adding an additional battery in parallel shouldn't require any other changes as long as you don't go crazy with additional loads. The idea here is to last longer with your current typical load, not to add additional load, as may be the temptation.
That...
I guess it depends on your current setup and how much room you have. My 310 came with 2 "house batteries" on one bank and one battery on the other. The house bank starts the genie and the starboard engine and runs †he cabin. The other bank starts the port engine and runs the helm electronics.
I...
Given your stated usage, I'd think 30 - 32' would be reasonable / minimum. Anything smaller likely precludes overnight guests, at least with any comfort. You didn't mention whether you expect to slip the boat or trailer it. That will have a huge impact on what is feasible.
Something to be wary of. I believe it was 2010? when Sea Ray began using model numbers that reflected LOA (including the swim platform). So a 2009 310 would be equivalent to a 2010 330. I may have the exact years wrong, but you get the idea.