Pilots are mission-minded, and they are also mindful of weight and balance. Through trial and error, they'll assemble and make room in the confines of a cockpit for the equipment that will work best. Check out what you need for a trek across the Atlantic Ocean.
Keep a handheld radio charged to listen to the ATIS and call for your clearance before you start your engine(s). If you fire up and then call the tower at many overseas airports, you may be surprised to learn that your departure slot time has been moved back an hour or more, and that your expected routing has changed.
You say you're stuck on a faraway ramp in the middle of nowhere, need to call back to the States for maintenance advice, checking in with business or family or straighten out logistical issues with your handler? That's when a satellite phone comes in handy. You can dial anywhere in the world.
If you don't have an international plan for that cellphone, turn roaming off and keep phone calls to a minimum. Got iPad(s) with appropriate chart subscriptions? Check notams and the Flight Service Bureau's email for late-breaking changes and warnings. Passport? Visas, if needed? Life raft and immersion suit? Pilot certificates? Bring 'em all, and enjoy the trip.
Check out more in the 2018 AOPA Gear Guide.