Question: I recently drove to Belgium and back via the Channel Tunnel. Should I have bentched gomel as I crossed the English Channel?
Answer: The Gemara (Berachos 54b) writes that in the times of the Beis Hamikdash, one brought a korban toda upon surviving a potentially life-threatening situation, including crossing a desert or a sea, imprisonment or serious illness. Nowadays, we substitute this offering with a public blessing, known as hagomel (Shulchan Aruch OC 219:2).
R’ Moshe Feinstein (Igros Moshe OC 2:59) explains that while boats nowadays are safer than ever before, the dangers of being in the sea remain. This is the reason why one benches gomel also after flying over water even though doing so is a safe means of transport (See Minchas Yitzchak 4:11:5).
The Shulchan Aruch (OC 219:7) writes that one doesn’t need to bench gomel when travelling from one city to another in Europe which doesn’t carry the same potential dangers as crossing a desert. The Biur Halacha (219:1) writes that accordingly, one wouldn’t bench gomel when crossing a river either.
R’ Shmuel Wosner (Shevet Halevi 9:72:3) and R’ Nosson Gestetner (Lehoros Nosson 7:10) write that the same applies to travelling through the Channel Tunnel. As the tunnel doesn’t have the potential dangers of travelling by sea, one doesn’t need to bench gomel.
In conclusion, while one would bench gomel if crossing the English Channel by boat or plane, one doesn’t do so if they took the Channel Tunnel.