I'm coming back to this after a while away, so apologize for rehashing anything...
We really value(d) owning rather than chartering, and here's why.
- No matter how good the charter company, they will never maintain the boat the way you will, and will not make improvements the way you will. A charter boat will work fine (hopefully), but will have minimal appoints and finishing touches. After all, it's a rental.
- When it's your boat, it's set up the way you want it, everything is where you want it and where you left it, you can keep better things on board like stabilizing binoculars, hand held VHFs, your favorite coffee maker, etc. and it won't be trashed when you return.
- You can keep all your own clothes and gear on board. I can't even imagine the amount of crap we'd have to bring for a 2 month charter if we were really going to fully enjoy the charter. Heck, two pairs of muck boots take up a full rolling suitcase by them selves, plus foul weather gear, etc. If you own the boat, all that stuff is there ready and waiting for you.
- Because the boat is ready and waiting for you, travel to the boat is easy. We typically only took a carry on bag with personal stuff, because everything else was on the boat. But did often have a second bag of parts, supplies, or whatever was more conveniently bought at home and hand carried.
- When you own the boat, you can go use it when you want, for how ever long you want, and if weather suggests a change in schedule, you can do it. Your constraints are limited to your own personal time constraints, not a fixed window in time, selected and committed to a year in advance.
- The boat will be the boat you want, not whatever happens to be available. You are talking about a 60ish foot boat. I don't think there are many of those for charter, and if there are, they are probably crewed boats which is a totally different experience.
- If your boat is in good shape, leaving it for months is just not a big deal. Rig up remote monitoring for a few vitals, have someone local who can check on things if there is a problem, then go. We always left power on , heat or HVAC on but at reduced temps, refrigerator and freezer on. Then when you return, all you need is some milk for coffee and you can move right back in. The grocery shop for perishables at your leisure, and push off the dock when you are ready.
- To leave the boat, have a good checklist. Turn off stuff other than the basics above, dispose of perishables, turn up or down the heat, and leave. And because you leave all the boat clothes and gear on the boat, your return trip is light on luggage too.
Now all of this ignores the comparative financials, and only you can assess how that factors in for you. But chartering isn't cheap, and if you are doing so for 2-4 months a year, it's hard for me to believe that's any cheaper than the carrying cost of owning a boat. If you own, you have cash tied up in the purchase cost, or more carrying cost in a loan, but if it's a good boat and well kept, you will get most of that back when you sell.