BSAC is a much more rigorous and thorough course.
Not really. At entry level the syllabus is pretty identical to all the others. Its a 20m depth not 18m and they can lift a casualty to the surface. They dont do BC or weight remove or replace underwater, CESA and a few other things.
Other than that, no difference. You can do it in 4 days just like a PADI course. You produce divers that can do all the core skills but have absolutely no diving experience just like PADI.
I have yet to see a poorly trained BSAC diver.
Ive seen many. One of the advantages is also one of the disadvantages. Very little oversight of clubs and a lot of things can depend on who you know or how much the guy doing the course wants to put in. There are standards but they're hardly enforced at all so you could get a very good course or a very choppy one.
A BSAC qual has an ISO and EUF equivalent so like all the others is accepted in any dive centre anywhere in the world without issue so that isnt a problem.
BSAC is a club so training tends to be more regimented to dates than PADI buisnesses who are charging you for the training.
Not strictly true. BSAC is also a commercial agency with schools just like any PADI dive centre where you pay your money and do your course. BSAC can also produce 4 day wonders "for-profit". Instructors can get paid through a shop just like PADI. Its not all club based.
As for the tables i dont think anyone seriously dives the BSAC '88 bendomatics but the key point to remember is these are decompression tables - BSAC allows mandatory deco diving so their tables allow to play for it (quite how sufficient the training is for deco diving is a different matter entirely). The tables are not based on hypothetical tissue models etc and are derived from a secret formula from the guy that made them. EAD apparently doesnt work on them according to him.
Brutal truth is for entry level courses if you do it through a school you're going to get pretty much the same training and content through BSAC as you will any other agency.
Club based training takes longer (typically 9 months to train a diver), has the same syllabus but they get LOTS more pool dives and OW dives in between so can emerge a lot more experienced doing it that way. However, due to the lack of oversight etc you may get skipped or poor club training depending entirely on the attitude and ability of the instructor in that club.
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Richard Whitcombe (BSAC OWI and Diving Officer of a BSAC Club. Also PADI MSDT).