Complex sentence: He had to crawl inside small spaces to do this, his superiors were wondering if he was doing his job so everywhere that Foo went he would write "FOO was here", this has been found on the wreckage of many subs and ships.
Split into simpler sentences: He had to crawl inside small spaces to do this, his superiors were wondering if he was doing his job so everywhere that Foo went he would write "Foo was here". This has been found on the wreckage of many subs and ships.