Resolving the number of demographically isolated populations and their boundaries is particularly challenging along continental coastlines where no obvious barriers to dispersal occur. This is a common scenario for marine turtles and many other marine species that use coastal areas for reproduction. Nonetheless, identifying the scale and degree of natal homing versus dispersal is critical for ensuring that demographically isolated populations have adequate protection at their reproductive sites. These data are also fundamental for identifying the appropriate scale for population monitoring. It is becoming increasingly clear that geographic distance alone is a poor indicator of the degree of potential isolation or connectivity among marine turtle nesting populations.