Hi Mspot welcome back
Individual speed settings are available by clicking on the advance toggle button at the bottom.
Hovering your mouse over the speed strip will show the speed where your mouse is.
Click to select it.
Snorkels can be used at any time in game play even though they were not used in the early part of the war.
So if you want a snorkel in 1939 then that is your choice.
Check out my tutorial post #6
Link to my SH5 – SH4 posts:
Step By Step Tutorials & How To Do It.
Also Included Are Some Useful Download Links
http://www.subsim.com/radioroom/showthread.php?t=211804
You can use TDW’Generic File Patcher with STEAM see my Tutorial Post #125
The Snorkel is the first tab.
You can make a manual saves also if you are worried about ctd's but it is not adviseable to do this if you are submerged.
Peter