Equipment

Electronics

AIS: To provide course and speed of shipping traffic, AIS will be utilized. While not likely to be utilized much for the "open water" portions of the trip, it can be highly valuable when approaching landfall with shipping converging on a small area. If single handed (especially), this can facilitate  alerting for approaching shipping/boat traffic.

Radar: Color radar can be used for weather and once again, especially if single-handed, alerting for approaching shipping/boat traffic.

Shortwave radio: An SSB radio with a Pactor modem facilitates email while underway: Radio package

Satellite phone: Satellite phones are now a viable (affordable) form of communication while at sea.

VHF radio: The boat will have a standard VHF radio with a remote mic in the cockpit.

Portable VHF: An additional portable VHF radio will also be aboard.

Provisions

Safety

Liferaft: a (recently) certified liferaft for the appropriate number of crew.
Go Bag: a properly stocked bag for abandoning ship: Contents to be named later
Immersion suit: Per an interview with Mario Vittone on a 59 Degrees North podcast, if you're sailing offshore you should prepare yourself for where you are going to be (the ocean wilderness) and in the worst of circumstances (alone in the water).
Boat EPIRB (Emergency Position Indicating Radio Beacon): Almost all boats carry at least one EPIRB these days.
Personal EPIRB: A personal locator beacon because (like Chris Rock says) ...you just never know...
Medical Kit: Of course this will include the expected: seasickness remedies, bandages, butterflies, etc. But for offshore purposes, additional items such as antibiotics, and other medications that may be necessary when far away from any direct medical assistance will also be required.
Checklists: I'm a strong believer in checklists. When stressed, people often forget things their rational minds know "by heart". I will have checklists for a variety of emergency situations.

Spares

Preparation for Europe

Things are different in Europe. Be prepared to avoid the costs and hassles upon arrival.

Power:
Water:
Passarelle: