Been away & just seen this post!
Jersey is very ski freindly.....as long as a few rules are obeyed!
Round the island is around 50-60 miles. We have done trips to Sark aswell as two offshore reefs...the Ecrehous & the Minquiers.....7 & 12 miles offshore respectively.
France is planned for August....only 17 ish miles from the closest point.
Minquiers is by far the best trip to do on a good day........the water is so clear down there. At low tide a sand bank is uncovered creating a lagoon.........a very special place!