Kinda late on this thread, but here is my Riyals worth
When I lived in Saudi not so long ago, boat dives were rare and expensive.
Shore dives on the other hand were plentiful and for many years more varied with cost being as little at less than one US$ for a tank of air, plus fuel costs, which back in the 90s was negligible, even now fuel in Saudi is 18 cents a litre.
There were two types of shore diving
1. From a private beach
Cost around $20 to enter, but showers available as well as toilets etc plus usually food available too.
Sometimes these beaches were rather busy especially at weekends.
2. From a public accessible area
We did a few dives in Jeddah itself, but the coastguard were always an issue, always tried to avoid them when going in but it could be hit an miss coming out.
The best part of Saudi is the long Red Sea coastline, most of it uninhabited and the fringe reef running along most of it. It took a little bit more organising some times (4x4 was useful), and we would frequently travel in groups of at least two vehicles and camp out over a weekend, but we managed to dive some incredible virgin reefs.
I probably have over 700 shore dives in Saudi, and since I left in 1997 I frequently go back to Jeddah on business and always manage to squeeze in at least a couple of dives.
Here in UAE, two dives from a boat cost around $100 minimum with my own gear, two shore dives in Saudi probably less than $10
The advantage of shore diving for me is;
1. The ability to dive more or less in my own time.
2. No rush to catch a boat.
3. Solo diving always an option
4. Early morning dives if camping or staying at a private resort.
5. Proper night dives if camping or staying at a private resort, although sometimes we did night dives off the north corniche in Jeddah itself with the added thrill of avoiding the coastguard.
One of my criteria for choosing a dive location on holiday is the option to shore dive