G' Day Kilted Dave,
Back in town. The data you are looking for can be found in several areas. The terms used in the Ship Logs are defined in the "G 2" summary on page vii while the "Ship Log" section of COMMISSINING provides a detailed example and explanations of warship, submarine and merchant Ship Logs on pages xii and xiii. Symbols for gunnery, torpedoes, mines and radar, etc. are also covered in their respective rule sections. Further, a blank Excel Ship Log file is available for download in the Bonus Files on the ODGW website with the format and symbols needed for those who wish to create their own Ship Logs. If you have reasonable familiarity with Excel, you can easily copy and paste the symbols as needed or generate them yourself to populate Ship Logs.
As Jeff noted in his 12 August 2024 post, the Deluxe Ship Logs have several supplemental symbologies which are detailed on the second page of the pdfs. An example is the Searchlight box noted in your inquiry.
Further, Shore Battery Logs are defined on page 1-23 and a similar "make your own" Excel file is provided for download in the Bonus Files on the ODGW website.
And, merchant ship terms and values are defined on page 1-29 and in considerably greater detail in the MSS (Merchant Ship System) supplement, a free download available in the ODGW Bonus Files. This supplement contains data for more than 400 cargo ships, tankers and transports along with numerous completed representative Ship Logs and an Excel file for creating your own.
Finally, I would add that there are a number of free GQ 3.3 download supplements for various other WW II navies, large and small, with Ship Logs for those navies you can access and several campaigns available for purchase which have completed Ship Logs for the campaign covered. A particular favorite of mine is the Sudden Storm Campaign which has completed Ship Logs for all the major ships of the IJN and USN (except Atlantic divisions) down to escorts and minesweepers, along with a detailed order of battle for both navies and air units, complete with the captain's or squadron commander's name in most cases. Interesting to see where many of the famous names you'll recognize from WW II were doing in 1937-1938. This was the result of several years detailed research through archives, etc. by a number of folks. Amazing what you can find if you dig enough. An intriguing window into a little know period where hostilities came far closer than most people realise. And, vey different from how WW II transpired.
Check out the pages and files described above and you'll be ready to understand all the data on Ship logs and create your own as well as have access to a large number of completed Logs for most of the navies in the WW II era.
Hope this clarifies things for you,
LONNIE