You can Teleport the crate onto the beach (breaking it) to get any loot that may be in it. You might be able to reach it with Telekinesis, but if so you'd need higher than level 2.
EDIT: nope, Telekinesis level 5 will not let you open the crate there.
In my last play with 173 i was able to open it normally by clicking on it. the char goes under the big stone in front of the wreck (Way back from the crate?!) and opens it ??!
