Filled with very useful and practical knowledge, this cave diving guidebook is also filled with Jill Heinerth's stunning underwater photographs. It is well designed, much more like a sophisticated magazine than a drab manual, and most techniques and procedures are illustrated with very high quality photos, filling a much-needed niche in the technical diving world. The author, acknowledged as one of the top cave divers in the world, has taken an extremely technical subject (cave diving) and presented it in a conversational, easy-to-understand format. Highly recommended for scuba divers at any level.