Found this in the help files, I assume this is my issue as I am now picking up other problems.
Example 2: Oracle 11g on Windows
The Oracle Database 11g Release 1 JDBC Drivers can be downloaded from:
http://www.oracle.com/technology/software/tech/java/sqlj_jdbc/htdocs/jdbc_111060.html
The ojdbc6.jar file, which is a JAR file that contains the JDBC Thin Driver for Oracle 11GR1, must be available to the application, specified using additional classes when starting the Java Dispatcher.
In the obsvr.properties file, the Oracle connection can be defined as follows:
Environment.Default.Driver=oracle.jdbc.driver.OracleDriver
Environment.Default.DataSource=jdb:oracle:thin:@mymachine:1521:orcl
Environment.Default.User=User
Environment.Default.User=Password