Hi,
this is obviously not from 1661, but more 19th c. by it's style, IMHO.
Immensi tremor oceani is the motto of the Order of Saint Michel.
This medal commemorates the year 1661 when king Louis 14 reformed this order, limiting the number of knights to 100. Source : https://fr.wikipedia.org/wiki/Ordre_de_Saint-Michel
The link with the Mont St Michel (France) isn't obvious, look's this medal is more common in Canada than in France :
Source : https://numicanada.com/forum/viewtopic.php?t=6418
I can't find another online…
About value, I don't think it has much…