I am a Navy Sailing E-MS and instructor rated skipper, as well as an ASA 201 through 205 instructor. I am the Training Commodore for a sailing club in Chesapeake Bay that awards over 80 Navy Sailing and ASA 101-103 certs each year, and about 30 of the higher level certs. We charter about 60 boats each year in Annapolis and the British Virgin Islands.
First of all, I want to echo all of the responses that have been made by contributors to this threead to your plans.
First of all, you feel that having ASA certs will get your foot in the door with a charterer. However, most charter companies are looking at the "whole package." The presentation of a qualification card or book loaded with stickers is not going to interest them by itself. A sailing resume is one thing that they are looking for. They will want to see evidence of experience. Another piece of paper that they are looking for is appreciation notes from other charter companies on how well you took care of their boat. They most important qualification that they will want is your credit card. They will want to see that they can hit it for at least the deductible on their insurance ($1,500 or higher).
You say that you have "found" a charter company that will let you charter based on a docking OTW evaluation that they will conduct for you. Whenever a chartering company tells you they need to see your skills demonstrated, then that means they have some doubts.They know that you have spent a lot of money in flying to their destination and are probably willing to fork out the money for a skipper vice turning around and flying back home when they tell you "sorry".
From what you have described, you have a lot of experience in 20 to 30 foot keelboats, but practically no experience in larger boats with auxiliary propulsion. I do not think that your demonstration will be "successful." The chartering company will then turn to you and say "OK..you will need to take a skipper with you that we will provide for you for $400 per day." It does not sound as though your pocket book is prepared for that.
In Annapolis, the chartering company we use (Annapolis Bay Charters)is familar with our training standards, and does not require skipper demonstrations. In the BVI, we normally use Horizon Charters at Nanny Cay Marina in Tortola. They do not require an OTW from us either. However, for most of the charterers (not us), Horizon doesn't generally let the charterers maneuver the boats in the marina. They take the boats to a safe T-head that the charterers can depart from.
Qualifications, whether they come from ASA, Navy Sailing, US Sailing, or the Royal Yachting Association simply demonstrate that you have demonstrated a minimum level of experience and skill. It is rare that any charter company would take a "qual card" at face value without also looking at a sailing resume. Keep in mind that a "forged" sailing resume will be viewed by most chartering companies as "negligence", which means if you have an "oops", you are paying the entire bill and the insurance company won't be a part of it.
As for your efforts at challenging the ASA certifications, the first thing that you need to realize is that all instructional facilities with any of the qualification organizations go through an inspection process, management plans, and ethics agreements to ensure that they are operating sound programs. ASA, for example, strongly discourages sailing qualification "puppy mills" where students with no experience start at ASA 101 on week one, and end up with ASA 106 on week five. The same holds true for challenges.
I entertain about 15 challenge requests each year at various levels. With only about 2 exceptions, the challengers overestimate their skills significantly. I usually ask them to take the requisite exams first. When they fail the exam (which will usually be the case), I will not have already waisted the time of instructor and, potentially, a crew to evaluate them.
Based on your skills to date, I would let you take the 101 and the 103 exams. If you passed, I would let you take an evaluation on a Capri/Catalina 22 with outboard propulsion. If you did well on the OTW, especially the marina maneuvering portion, I would give you your 101 and 103.
However, I would not consider you for 104/105 without your having taken a 2 day classroom piloting course and an additional 86 hours of day sailing and 20 hours of night sailing on a 30 foot plus boat with inboard auxiliary propulsion. As part of that experience, you would get practical training on how to conduct a visual navigation plot. I don't know of anyone who has passed the 105 without having had practical experince with piloting first. This experience would also include lots of close quarter maneuvering in a marina, reefing and sail trim training, use of preventers, diesel operation and basic repair, electrical sytem training and casualties, propane stove usage, anchoring, basic weather, contact management, VHF communications, man overboard techniques, use of jack lines, and mooring to a buoy. You would also have needed to have demonstrated every sailing skill on the ASA examination forms for 104, and a repeat of the 103 skills.
I am sorry to say this, but I think that you are overestimating your skills for this adventure and could find yourself in a great deal of trouble. I know that you want to get out there in the big boats and the big water without spending a lot of money. But what you won't want is the feeling of fear or frustration on your part or the part of your crew when something comes up that you can't handle. It will become very apparent to everyone very quickly when you can't, and it will kill their confidence in you as a skipper. Most of all, you don't want the situation to deteriorate into boat damage or personal injury.
There is an ASA school not very far from you....Sail Western Colorado
I would send the owner a note and see if he would let you challenge 101 and 103. You will want to do that the day prior to the actual 101 and 103 class. If you don't make the grade, then you can stick around and take their three day class for $600. They offer the 104 as part of their BVI cruising program. Going as crew will cost less than chartering a boat yourself, and you will gain valuable experience.