Sorry, I could have been indeed more precise. But it's Your job to know the ship You're drawing, not mine.
Do I understand correctly, that You've been trying to make this drawing based on 1 photograph only?
There seems to me, that there is searchlight and a siren in front of the open bridge.
Re: SB-standard railings. I was initially annoyed by that rule, but believe me - they are friends of the beginner. They allow to hide a lots of small, hard-to-draw details. One just needs to draw enough to signal that the particular thing is there, and the rest will be hidden behind the railing.
Try to look on the photographs of the other ships of the class, it seems to be fairly standarized type.
That's my attempt to do this ship. Wrong color, but I've made it already on friday, and based on Your first version, merely for fun. I put the RHIB aside (away for maintenance of something
), didn't include the radar and some other stuff etc.