[AtlasBarfed]

Channel crossing is usually critically aided by timing tides that help suck you out when leaving England, and suck you in as you approach France.

https://www.channelswimmingassociation.com/swim-advice/chann...

[patrakov]

Is the EN -> FR direction in your post just an example, or is there indeed a significant difference in difficulty?

[TwistedWave]

From the association’s website, you can learn :

France/England swims are no longer permitted. When the French authorities permitted these they usually started from Cap Gris Nez.