Our contacts tell us that at last pretty much all wrecks from Hurricane Irma (Sept 2017) have been cleared which makes navigation and anchoring the Lagoon much safer!
Obviously anchoring in the channels or in front of the marinas is forbidden.
When anchoring on the Dutch Side, a fee will be charged.
Smaller yachts can enter through the French bridge (width bridge = 10m) and anchoring is free in the French part of The Lagoon
Marigot Marina Fort Louis’s website offers clear info on all bridges (including Causeway Bridge). https://www.marinafortlouis.com/bridge-opening-times.html