"Man battle stations missile, set condition 1SQ, spin up all missiles, this is WSRT"

This is an announcement over the loudspeakers that you heard many times during your service on an SSBN. This statement contains 3 orders and one very important tidbit of information.

Order #1 Man Battle Stations Missile - A battle station is an assigned position or watch station that you report to when entering battle conditions. On a submarine you can fire torpedoes or missiles so the announcement should specify which battle condition to expect because you may not have the same station for both. My station for missile was the Auxiliary Throttle Control Station. For torpedo it was the aft Hydraulic Control Station for the planes.

Order #2 Set condition 1SQ means to prepare your battle station to the highest degree of readiness for action Example, the Hydraulic Control Station required a series of valve manipulations to take over control of the planes from the helmsman. Some of these valves had locks to prevent accidental operation. I had to remove the locks and set the valve lineup with the exception of the last valve which would cut off control hydraulics to the helmsman.

Order #3 Spin up all missiles - Prepare the missiles for launch, input targeting data, prime the launch motor.

"This is WSRT" means Weapons System Readiness Test. It's a drill. For drills there were some actions you only simulated especially those involving control of the sub and condition of the missiles. If you heard the above announcement without that last little tidbit of info then it's not a drill and it's about to get serious.

In the movie I believe they were prepping to engage to Soviet sub when that announcement was made

https://www.quora.com/What-does-set-for-condition-1SQ-from-the-movie-Crimson-Tide-mean