Two shoreline notes report eight objects and twelve objects. Without knowing where each observer looked, the larger number cannot tell us which stretch had a greater concentration.
Give the count a boundary
For a paper exercise, draw two imaginary sections of shore. Make one twice as long as the other and mark the areas actually inspected. State whether the observation includes the path edge, exposed beach or another defined zone.
A place name alone may cover much more ground than a person examined. The notebook should make that difference visible.
Separate searched from unsearched
Shade any part that could not be observed. Do not record an inaccessible patch as containing zero objects; zero would imply a count was made there.
On a real visit, stay within permitted and safe public areas. A tidy comparison is never a reason to enter water, disturb habitat or cross a closed boundary.
Write a reproducible sentence
For the imaginary exercise, a useful note might specify a marked path section, the side viewed, the duration and what counted as an object. Another reader can then see what a repeat observation would need to match.
This expands the method question in shoreline debris counts. The boundary is part of the result, not a minor detail to add after the total has been compared.