The First time the gentlemen say "HERE WE GO!" and embark down the ramp to cross the channel is a song written by english composer James Seymour Brett. Early in his career he wrote a few cues to be part of a Stock Music collection (not sure the name). This track titled "Invincible" is from that album. Both times when the enter the water and their is good music (1: Whimsical, 2: Triumphant) are both by James Seymour Brett. His website (
www.jamesseymourbrett.com) is amazing if you listen to his current projects: Batman (a live action show that stays true to the Elfman sound), and Walking with Dinosaurs (a robotics type show that is so beautiful. Even his work on a self made project "The Book of Musical Magic" to me shows he couldn've been a good option for the Harry Potter series after the departure of John Williams. I hope I have helped, and know this is a long time since your post.
Happy Listening,
ZPIANOGuy