What's the Most Affordable Boat to Escape (1 Way Trip) SHTF?

I could live on my boat for about 2 months as it sits right now, and if I had time to prep the boat, I could probably extend that to 6 months! I would actually LOVE a bigger boat, but fuel use goes up as the boat gets bigger. I have even been looking as ocean going tug boats as a possibility, and there are some in the size range I would be interested in that have a pretty good fuel to size ratio with the added side benefits a boat like that would give, like deck space for housing a small work boat, and a couple of motorcycles, and maybe even a 4X4 pickup!!! Having the advantage of running bunker C or #5 diesel makes fuel super cheap and really available and post shtf, very few small boats will be able to run this fuel, so it's going to be even more available!
My bride and I have spent quite a bit talking about this, as we are both wanting more options for getting out of the country should things really go south in the U.S. and/or the rest of the world, and a good size tug would offer security due to it's size and a good field of view, plus plenty of usable space for needful things!

 

It would also have the grunt to pull the barge that stores even more needful things...you may need a few carronades on tug and barge to sort out the pirates that may come your way....

 

1 3/4" swivel guns go for less than a grand...

 

If you are escaping LA from a tsunami ,by water is not a safe option .
There is still footage on you tube of the tsunami in Japan. take a good long look.

 

Yeesh. The man asked about one time use and affordable boat. Reading all the above tells me he's barking up the wrong tree (again.)

That said, the tug boat scheme is good, east or west coasts. In the northeast, there are some retired trawlers that have been re-purposed as liveaboards, with some success; large cargo holds that become living spaces, some luxurious. Neither trawlers nor tugs are particularly efficient of fuel, being designed to run hard and are optimized for heavily loaded running. And I ain't betting on survivability in a tsunami, but the chances are better with those than a kayak.

@Ura-Ki Bad news, I fear, to go with a good idea. Bunker C takes very special handling equipment, and I can about guarantee that you'll find nothing smaller than a liberty ship that can use it. For sure (further deponent showeth otherwise) there are no east coast tugs or trawlers that can heat it up and inject it. Cheap to buy, yes, but really costly to use. I had the good fortune to design a static boiler fuel system around bunker C, so I've a bit of old (20 years ago) knowledge about that tar. The fact remains, you can almost walk on it in a tank.

 

Another thing to consider is living on the boat 24/7.
Some people live aboard while their boat is either on a buoy or in a slip, use a skiff to go ashore and have a car or motorcycle to drive to work .
This for 3 reasons.
1. maintenance is a constant with a boat , it still ages whether your using it or not.
2.people will be stealing any thing to escape ,if things are that frantic.
3. getting to the boat , might be a serious challenge .
4. if you are renting a slip or a buoy any way and all your stuff is aboard ,living aboard reduces the out side expenditures.
It would be like owning a trailer/motorhome in a trailer park . things get bad hook and haul. only in the case of a boat, unhook and set sail.
I realize that the OP was only interested in an escape plan using a boat, but if you've got to drive to the ocean ,it may not be as easy as it sounds, especially the LA area and if there is that significant an earth quake.