Well according to the last post it could only help right?
It is going to work both ways on this one, your comfort in the water from already being a diver is going to be an advantage but for the rest I would really make sure your payin attention to how the material is being taught even if you do not understand why it's taught that way.
The dive school trains you to be a self sufficient commercial diver, you will rarely dive with a buddy outside training unless your training under a experienced diver or in the future training a new guy. This is the case in both surface supplied and SCUBA operations. You will almost always be diving with some type of tether to the surface. a tending line in SCUBA and an umbilical in surface supplied.
The medicine, physiology, and physics training is going to be much more in depth than most recreational programs. UYour being training to conduct decompression diving, treat diving related injuries (AGE and DCS) on-site. You will be the one running the chamber even in school...
The SCUBA portion is going to lose the highest number of people, your going to have problems imposed on you including removal of your equipment (including your tanks if they can get them) and you have to remain calm and collected and fix the problem, going to the surface is not going to be an option during this training.
Many people have done it before you and many will do it after you, nothing impossible and nothing every instructor has not done themselves.
As far as diving I personally resent the comments to the effect that Navy divers suck, just shows your ignorance making blanket statements about a group of divers so large and diverse, especially considering the history behind the program. Ever wonder why a Navy diver would be taking training from a recreational instructor anyway? Did you see their dive card?
One point I will most certainly concede is the area of buoyancy control, working commercially your going to be diving overweighted nearly all the time. One reason is you need the weight to get any type of leverage when working. The other reason your most often working on the bottom not in the water column.
In closing if you have specific questions please feel free to contact me privately
jlane@adp.fsu.edu
and for those of you so intimidated by Navy diving that you feel you have to attack the level of proficiency I feel nothing but pity...
Your never going to convince yourself your good by talking, get in the water and dive.