No, I use 1280*1024 as well.
I tried to measure the lengths of the bearing tool on your screenshot and mine with a real ruler and they appear to be the same. So IMO the problem is the ruler tool.
The mod I use are (even if I don't think they are involved):
-TriggerMaru 1.3
-Combined uniform dolphin pin
-Metric speed chart help
-Tmaru repeat patrol fix
-Tmaru subs stock fuel
-Telemeter lens 32 dgr
-OAKsHudGauges
-360 degree bearing tool 1.4
-Realistic creew ranks