SSI Open Water Diver Section 1 2026/2027 – 20 Questions & Answers | Pressure, Equalization, Ear & Sinus Squeeze, Light & Sound

This SSI Open Water Diver Section 1 2026/2027 study guide contains 20 exam questions with correct answers across 5 pages, covering fundamental concepts of pressure, air volume, equalization, ear and sinus squeeze, underwater light and sound, heat loss, and differences between saltwater and freshwater. The material includes calculations and definitions involving absolute pressure, gauge pressure, atmospheres absolute (ATA), and changes in air-filled container volume with depth, including the example of a 40-cubic-foot flexible container decreasing to 10 cubic feet at 99 feet in seawater. A major section focuses on pressure and equalization during descent. According to the study material, the greatest relative pressure change in seawater occurs between 0 and 33 feet, while absolute pressure reaches 2 ATA at 33 feet and 4 ATA at 99 feet. Equalization is described as introducing additional air into body air spaces in response to increasing external pressure. The questions review techniques such as swallowing, rotating the jaw, and the Valsalva maneuver, as well as the document's guidance to stop descending and ascend until discomfort resolves if ear pain occurs. The guide also reviews ear and sinus squeeze prevention, stating that proper equalization helps prevent squeeze injuries, ear pain, and sinus squeeze. It identifies sharp pain or a wedging sensation above the eyes as an initial symptom of sinus squeeze and advises against diving with a cold. The source also states that earplugs should not be worn while diving. These questions provide focused revision of the pressure-related concepts presented in Section 1. Additional questions cover the underwater environment and basic diving physics. The document states that refraction makes objects appear closer underwater, while absorption causes certain colors to diminish with increasing depth. It describes sound as traveling faster and farther underwater while making its direction more difficult for divers to determine, and states that the body loses heat underwater 25–30 times faster than in air. The material also gives water densities of 64 lb/ft³ for saltwater and 62.5 lb/ft³ for freshwater and defines absolute pressure as the total pressure exerted on an object. Professional Reference: For additional training context, Scuba Schools International (SSI) is the official organization behind SSI diver education and certification programs. Because diving is a practical safety activity, students should use the uploaded questions as revision material and follow their current SSI training materials and instructor guidance for actual diving procedures. Relevant students: This document is particularly relevant to SSI Open Water Diver students, beginner scuba divers, recreational diving students, entry-level scuba certification candidates, and learners preparing for an SSI Section 1 knowledge assessment. It is especially useful for reviewing Boyle’s-law-style pressure and volume concepts, ATA calculations, equalization, ear and sinus squeeze, underwater optics, sound transmission, heat loss, and saltwater versus freshwater properties. No university or conventional academic course code is identified in the document. Keywords: SSI Open Water Diver Section 1, SSI Open Water Diver exam , SSI Open Water Diver questions and answers, SSI Section 1 exam, SSI scuba exam, open water diver study guide, scuba diving questions and answers, scuba pressure questions, absolute pressure diving, gauge pressure diving, ATA scuba diving, pressure and volume diving, equalization scuba diving, ear squeeze diving, sinus squeeze diving, Valsalva maneuver diving, underwater pressure, 33 feet 2 ATA, 99 feet 4 ATA, underwater light refraction, light absorption underwater, underwater sound transmission, scuba heat loss, saltwater freshwater diving, scuba diving physics, SSI certification exam, beginner scuba diving, open water certification study guide