Since no one else mentioned it, I guess I will..... Don't you have the required dive flag?
Exactly where I was going. Most ops that I've dove with in that area want you to tow the required dive flag (or hire a DM to tow it for you). If you're already towing a flag, you don't need to shoot an smb. You typically don't even need to bring a flag, as the op will proved them. Check with your op first, of course.