Ali3,
I really hate repeating Par

so I will add some specific issues I don't think you fully understand.
Your idea of an electric powerboat is not possible, and there are a number of threads here discussing it, but the short answer is that you need something like 100lbs of batteries for every lb of diesel they will replace. Now to do a trip across the Atlantic figure you need a range of 4,000 miles. A small boat will motor at about 4kn/hour. And burn about a gallon an hour on the engine. So to travel across the Atlantic you need to carry 1,000 gallons of fuel, which equates to around 7,000lbs of diesel fuel, to convert tht to batteries you would then have to carry 700,000lbs of diesel to replace the diesel fuel.
While these numbers seem ridiculous, just keep in mind that diesel has an energy density more than 100 times that of batteries. You could try to use solar panels to generate the power you need instead of using battery storage. But that same small motor is going to be something like a 10kw motor... Now if you are using 10kw/hr over 24 hours you will need to generate 240kw/hr over the course of the day for propulsion. Since most solar panels only generate for 8 hours in 24, you will need a solar panel rated at over 750kw to power your little engine.
In short it doesn't work, and solar panels don't help much. The only realistic way to cross oceans in a small boat (less than 25 foot) is under sail, or with a tremendous amount of money spent on a record breaker or some sort.
As for building a small boat because it is easier to transport... It costs a few thousand dollars to move a large boat by trailer. This likely wouldn't even cover the cost of the food for such an undertaking. It is a poor place to try and save money. In addition a small boat makes everything harder. Everything must be highly engineered and thought out because there is no room for error, or for extra gear to make life enjoyable.
I have a friend who races in the Open 6.5 circuit. When he leaves he has exactly one pair of shorts, and one shirt with him. He weighs the water on board, and the food, and the toothpaste. Because there just isn't room for extra anything. What you intend is a wonderful trip, and experience, but living through it should not be left up to chance.
Again please spend a few years (yes years) learning about how to approach this safely. Crossing an ocean on a small boat is an imminently dangerous activity, it can be done, but to do it safely is not even close to the same thing as taking even a week long cruise. It is a major undertaking and even life long sailors have been killed attempting it.