One U-joint on drive shaft

[Sergy]

Hi everyone my 25 year old boat has a U-joint about 2 “ after coupling it works fine I have no problems I am sure the previous owner must of installed to correct some minor misalignment. Has anyone ever seen this is it a good or bad idea . There is about 5 inches from back of U-Joint to stuffing box. I have considered placing some kind of brace that would retain the shaft in the center if ever the shaft were to break