I have been a liveaboard for 10 years crossed oceans and one of the scariest thing I have done was crossing the English Channel.
Tie your ankles together with about a foot of slack, now imagine crossing a motorway.
It is BUSY out there and the big boys can't slow down in a hurry or change course in a hurry.
What sort of boat were you thinking of using for the crossing? If it is a 12 to 14 foot dinghy
a support boat might be a sensible safety option.
It is clearly possible to do it even in something like a Oppie but the rope between your ankles gets shorter.