markers inaccurate

Hi, I’m new to using OSM. I have a wordpress site that uses an OSM plugin to display places I’ve been. I use a marker file with a list of lat/long to tell it where the markers should be. I noticed that my markers are all offset until I zoom in. I noticed because several for coastal cities are out in the ocean. I got the lat/long’s from google earth. How do I correct this so that my markers show up in the correct location at all zoom levels?