Forfoxake is entirely correct! I do however, disagree with Forfoxake's statement of uselessness of lifejackets. The water temperature of the Channel rarely decreases to below 6 degrees during daylight hours throughout the winter months, giving you a good 30 minutes to 1 hour estimated survival time prior to hypothermia kicking in. The Channel has a tendency of being particularly busy, and boats are often a short sail away. If you ditched near(ish) a boat, the lifejacket could afford you a good margin for survival in the Channel which could easily be the difference between life or death as they prepare a tender or sail towards you. During the summer months, the water temperature is such that it could mean time to hypothermia could be well in excess of 5 hours. However, I am not sure that physical fitness would keep a normal person swimming / keeping afloat for 5 hours - the lifejackets definitely will, allowing again a safe margin. Definitely agree that carrying a liferaft is an excellent idea though.
Forfoxake's statement about police / PPR notification at your destination really needs careful attention, but also, consider the French plates, some airfields are French only on frequency, it would be wise to read up on common phrases in French used on the radio to attempt to build a proper mental picture.
Timmydd, I would recommend also taking a copy of interception notes, and having read through these, PLB / ELT (if fitted / required - depends on the country), and your / passenger's passport(s)! Very important!! Always check prior to getting into the plane both your and your passenger's passports, including expiry dates!
Good luck and have fun!!
Alex