[\/et_pb_text][\/et_pb_column][et_pb_column type=”1_2″ _builder_version=”4.22.0″ _module_preset=”default” custom_padding=”||||false|false” global_colors_info=”{}” custom_padding__hover=”|||” theme_builder_area=”post_content”][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”1_2,1_2″ make_equal=”on” _builder_version=”4.22.0″ _module_preset=”default” background_size=”initial” background_position=”top_left” background_repeat=”repeat” max_width=”100%” module_alignment=”center” custom_padding=”||||false|false” use_custom_width=”on” width_unit=”off” custom_width_percent=”100%” global_colors_info=”{}” theme_builder_area=”post_content”][et_pb_column type=”1_2″ _builder_version=”4.22.0″ _module_preset=”default” custom_padding=”||||false|false” global_colors_info=”{}” custom_padding__hover=”|||” theme_builder_area=”post_content”][et_pb_image src=”https:\/\/courses.asiascubainstructors.com\/wp-content\/uploads\/2024\/09\/PADI-IDC-theory-handsignals-1.jpg” align_tablet=”center” align_phone=”” align_last_edited=”on|desktop” _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}” theme_builder_area=”post_content”][\/et_pb_image][et_pb_image src=”https:\/\/courses.asiascubainstructors.com\/wp-content\/uploads\/2024\/09\/PADI-IDC-theory-handsignals-2.jpg” align_tablet=”center” align_phone=”” align_last_edited=”on|desktop” _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}” theme_builder_area=”post_content”][\/et_pb_image][\/et_pb_column][et_pb_column type=”1_2″ _builder_version=”4.22.0″ _module_preset=”default” custom_padding=”||||false|false” global_colors_info=”{}” custom_padding__hover=”|||” theme_builder_area=”post_content”][et_pb_image src=”https:\/\/courses.asiascubainstructors.com\/wp-content\/uploads\/2024\/09\/PADI-IDC-theory-handsignals-3.jpg” align_tablet=”center” align_phone=”” align_last_edited=”on|desktop” _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}” theme_builder_area=”post_content”][\/et_pb_image][et_pb_image src=”https:\/\/courses.asiascubainstructors.com\/wp-content\/uploads\/2024\/09\/PADI-IDC-theory-handsignals-4.jpg” align_tablet=”center” align_phone=”” align_last_edited=”on|desktop” _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}” theme_builder_area=”post_content”][\/et_pb_image][\/et_pb_column][\/et_pb_row][et_pb_row use_custom_gutter=”on” gutter_width=”1″ make_equal=”on” _builder_version=”4.22.0″ _module_preset=”default” background_size=”initial” background_position=”top_left” background_repeat=”repeat” max_width=”100%” module_alignment=”center” custom_padding=”0px||||false|false” locked=”off” global_colors_info=”{}” theme_builder_area=”post_content”][et_pb_column type=”4_4″ _builder_version=”4.22.0″ _module_preset=”default” global_colors_info=”{}” theme_builder_area=”post_content”][et_pb_text _builder_version=”4.22.0″ _module_preset=”8b1f8231-1210-4c64-bae4-d177be5c655c” background_color=”#FFFFFF” custom_padding=”5%|5%|5%|5%|true|false” hover_enabled=”0″ locked=”off” global_colors_info=”{}” theme_builder_area=”post_content” sticky_enabled=”0″]<\/p>\n
| <\/span> History: The clenched fist signal<\/strong><\/span><\/p>\n In the early days of diving, before submersible pressure gauges (SPGs) were common, divers relied on a piece of equipment called the J-valve. This special valve had a built-in reserve mechanism. When the tank’s air pressure dropped to about 20-40 bar, the J-valve would restrict the airflow, signaling the diver that they were low on air. To restore airflow and access the remaining reserve air, the diver would have to reach back and pull a lever (J-rod) on the tank.<\/p>\n The diver would signal his buddy with a short pulling motion to indicate that he had activated his reserve. As a result, the hand signal for \u201clow on air\u201d \u2014 a clenched fist placed on the chest \u2014 naturally evolved from this gesture.<\/p>\n In this picture you can see the J-rod (the thin rod held by two black bands on the tank) on the divers’ tank (taken from the cover of the 1966 Aqualung catalog).<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row make_equal=”on” _builder_version=”4.22.0″ _module_preset=”default” background_size=”initial” background_position=”top_left” background_repeat=”repeat” max_width=”100%” module_alignment=”center” custom_padding=”||||false|false” use_custom_width=”on” width_unit=”off” custom_width_percent=”100%” global_colors_info=”{}” theme_builder_area=”post_content”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”||||false|false” global_colors_info=”{}” custom_padding__hover=”|||” theme_builder_area=”post_content”][et_pb_text _builder_version=”4.22.0″ _module_preset=”4ff8d2da-4780-4f30-96ef-a867e11f48be” global_colors_info=”{}” theme_builder_area=”post_content”]<\/p>\n The controlled emergency swimming ascent<\/strong><\/em> should be done with all equipment in place \u2013 the diver should keep his weight belt on and his regulator in his mouth. Retaining the regulator in the mouth is important because it helps to keep the airways open and the diver may get a last breath from the tank as the surrounding pressure becomes lower when approaching the surface.<\/p>\n The diver should kick to start the ascend and then swim slowly at a rate not to exceed 18m\/min. He should have his right hand above his head and hold the low-pressure inflator up with his left hand. He should look up and make a continuous ‘aaah’ sound, exhaling through the entire ascent.<\/p>\n Upon reaching the surface, the diver should establish positive buoyancy by either dropping his weights or orally inflating his BCD (or both). The correct procedure to perform an emergency weight drop is to use the quick release of the weight system and pull the weights clear from your body.<\/p>\n <\/p>\n <\/p>\n When diving in a new environment, with new equipment or after a period of inactivity, it is advised to perform a buoyancy check<\/strong><\/em> at the surface before starting the dive. While resting vertically in the water and with all equipment in place, without finning or sculling and while holding a normal breath, the diver should float at eye level. If not, the weight system can be adjusted.<\/p>\n As a final check, the diver should breath out and sink slowly.<\/p>\n <\/p>\n <\/p>\n Sending up a DSMB (delayed surface marker buoy) before ascending to the surface is very important to show your position and to warn boat traffic. After inflating the buoy, hold on to the reel while keeping tension on it. Hold the reel in your hand and never clip it to your BCD or other equipment.<\/p>\n <\/span><\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row make_equal=”on” admin_label=”Class Details Area” _builder_version=”4.16″ _module_preset=”default” background_size=”initial” background_position=”top_left” background_repeat=”repeat” max_width=”100%” module_alignment=”center” custom_padding=”||||false|false” use_custom_width=”on” width_unit=”off” custom_width_percent=”100%” locked=”off” global_colors_info=”{}” theme_builder_area=”post_content”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”|5%||5%” custom_padding_tablet=”” custom_padding_phone=”|0px||0px” custom_padding_last_edited=”on|phone” global_colors_info=”{}” custom_padding__hover=”|||” theme_builder_area=”post_content”][et_pb_image src=”https:\/\/courses.asiascubainstructors.com\/wp-content\/uploads\/2024\/09\/PADI-IDC-theory-dsmb.jpg” force_fullwidth=”on” align_tablet=”center” align_phone=”” align_last_edited=”on|desktop” _builder_version=”4.16″ _module_preset=”default” custom_margin=”||” global_colors_info=”{}” theme_builder_area=”post_content”][\/et_pb_image][\/et_pb_column][\/et_pb_row][et_pb_row make_equal=”on” _builder_version=”4.22.0″ _module_preset=”default” background_size=”initial” background_position=”top_left” background_repeat=”repeat” max_width=”100%” module_alignment=”center” custom_padding=”||||false|false” use_custom_width=”on” width_unit=”off” custom_width_percent=”100%” global_colors_info=”{}” theme_builder_area=”post_content”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”||||false|false” global_colors_info=”{}” custom_padding__hover=”|||” theme_builder_area=”post_content”][et_pb_text _builder_version=”4.22.0″ _module_preset=”4ff8d2da-4780-4f30-96ef-a867e11f48be” global_colors_info=”{}” theme_builder_area=”post_content”]<\/p>\n When diving in a mild current, the general advice is to start the dive against the current and return to the entry point with the current. Currents are generally stronger near the surface so when diving against the current it is advised to stay close to the bottom.<\/p>\n Near underwater pinnacles and steep drop-offs, downcurrents<\/strong><\/em> can occur. Most likely, downcurrents are caused when opposing horizontal currents meet and water is pushed down. It usually follows the local topography, such as down a wall. <\/p>\n <\/span><\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”1_3,2_3″ make_equal=”on” _builder_version=”4.22.0″ _module_preset=”default” background_size=”initial” background_position=”top_left” background_repeat=”repeat” max_width=”100%” module_alignment=”center” custom_padding=”||||false|false” use_custom_width=”on” width_unit=”off” custom_width_percent=”100%” global_colors_info=”{}” theme_builder_area=”post_content”][et_pb_column type=”1_3″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”|||0px” custom_padding_tablet=”” custom_padding_phone=”|||0px” custom_padding_last_edited=”on|desktop” global_colors_info=”{}” custom_padding__hover=”|||” theme_builder_area=”post_content”][et_pb_image src=”https:\/\/courses.asiascubainstructors.com\/wp-content\/uploads\/2024\/09\/PADI-IDC-theory-negative-entry.jpg” force_fullwidth=”on” align_tablet=”center” align_phone=”” align_last_edited=”on|desktop” _builder_version=”4.16″ _module_preset=”default” animation_style=”fade” animation_delay=”500ms” global_colors_info=”{}” theme_builder_area=”post_content”] [\/et_pb_image][\/et_pb_column][et_pb_column type=”2_3″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”||||false|false” global_colors_info=”{}” custom_padding__hover=”|||” theme_builder_area=”post_content”][et_pb_text _builder_version=”4.16″ _module_preset=”4ff8d2da-4780-4f30-96ef-a867e11f48be” global_colors_info=”{}” theme_builder_area=”post_content”]When diving a relatively small dive site in a strong current it can be useful to make a ‘negative entry’<\/strong><\/em>. The diver completely deflates his BCD and descends immediately after entering the water. Be aware that small equipment problems like defogging your mask should be solved before entering the water.<\/p>\n When drift diving in a group sometimes a float<\/strong><\/em> (with line and reel) is used to keep the group together. The line handler descends first and the group stays behind the line handler during the dive. The line handler should never clip the line to his BCD or other equipment.[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row make_equal=”on” _builder_version=”4.22.0″ _module_preset=”default” background_size=”initial” background_position=”top_left” background_repeat=”repeat” max_width=”100%” module_alignment=”center” custom_padding=”||||false|false” use_custom_width=”on” width_unit=”off” custom_width_percent=”100%” global_colors_info=”{}” theme_builder_area=”post_content”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”||||false|false” global_colors_info=”{}” custom_padding__hover=”|||” theme_builder_area=”post_content”][et_pb_text _builder_version=”4.22.0″ _module_preset=”4ff8d2da-4780-4f30-96ef-a867e11f48be” global_colors_info=”{}” theme_builder_area=”post_content”]<\/p>\n When searching for a medium to large size object the preferred search pattern is an expanding square pattern<\/strong><\/em>. To navigate an expanding square you count your kick cycles and make 90 degree turns, adding one or more kick cycles after every turn. The number of kick cycles to use depends on the visibility, bottom topography and the size of the object. The main advantages of an expanding square pattern are that there is no special equipment needed and that eventually the entire search area is covered.<\/p>\n If the search area is restricted, for instance by a reef or beach, it is possible to use a U-shaped search pattern<\/strong><\/em>. Again the number of kick cycles to use depends on the visibility, bottom composition and the size of the object. To swim a U-pattern, make two 90 degree turns to the left, followed by two 90 degree turns to the right and so on.<\/p>\n <\/span><\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”3_5,2_5″ make_equal=”on” _builder_version=”4.22.0″ _module_preset=”default” background_size=”initial” background_position=”top_left” background_repeat=”repeat” max_width=”100%” module_alignment=”center” custom_padding=”||||false|false” use_custom_width=”on” width_unit=”off” custom_width_percent=”100%” global_colors_info=”{}” theme_builder_area=”post_content”][et_pb_column type=”3_5″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”||||false|false” global_colors_info=”{}” custom_padding__hover=”|||” theme_builder_area=”post_content”][et_pb_text _builder_version=”4.16″ _module_preset=”4ff8d2da-4780-4f30-96ef-a867e11f48be” custom_padding=”||5%|” global_colors_info=”{}” theme_builder_area=”post_content”]A circular search pattern<\/strong><\/em> can be used to search for small objects. One diver positions himself at the center, holding a reel. Another diver holds the end of the line and swims in a circle. After a full circle, the center diver feeds more line. The main disadvantages are that the search area is limited in size and the bottom topography (obstructions) can cause difficulties. Alternatively, it is possible to use a semi-circular pattern.<\/p>\n If the search area has many obstructions on the bottom it is possible to use a jackstay pattern<\/strong><\/em>. Start by establishing one edge of the search area as a baseline. Stretch a rope perpendicular to the baseline and use this as a search reference. This rope is moved along the baseline until the object is found or the dive limit is reached.[\/et_pb_text][\/et_pb_column][et_pb_column type=”2_5″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”|0px||5%” custom_padding_tablet=”” custom_padding_phone=”10%|||0px” custom_padding_last_edited=”on|phone” global_colors_info=”{}” custom_padding__hover=”|||” theme_builder_area=”post_content”][et_pb_image src=”https:\/\/courses.asiascubainstructors.com\/wp-content\/uploads\/2024\/09\/PADI-IDC-theory-search-patterns.jpg” force_fullwidth=”on” align_tablet=”center” align_phone=”” align_last_edited=”on|desktop” _builder_version=”4.16″ _module_preset=”default” animation_style=”fade” animation_delay=”500ms” global_colors_info=”{}” theme_builder_area=”post_content”] [\/et_pb_image][et_pb_text _builder_version=”4.16″ _module_preset=”4ff8d2da-4780-4f30-96ef-a867e11f48be” text_font=”||||||||” custom_margin=”-50px|5%||5%” custom_padding=”10px||” locked=”off” global_colors_info=”{}” theme_builder_area=”post_content”]<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row make_equal=”on” _builder_version=”4.22.0″ _module_preset=”default” background_size=”initial” background_position=”top_left” background_repeat=”repeat” max_width=”100%” module_alignment=”center” custom_padding=”||||false|false” use_custom_width=”on” width_unit=”off” custom_width_percent=”100%” global_colors_info=”{}” theme_builder_area=”post_content”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”||||false|false” global_colors_info=”{}” custom_padding__hover=”|||” theme_builder_area=”post_content”][et_pb_text _builder_version=”4.22.0″ _module_preset=”4ff8d2da-4780-4f30-96ef-a867e11f48be” global_colors_info=”{}” theme_builder_area=”post_content”]<\/p>\n Recreational search and recovery divers are trained to use a lift bag to lift objects to a maximum of about 45 Kg. Never use your BCD for lifting objects that weigh more than about 4 – 7 Kg. <\/span><\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row make_equal=”on” _builder_version=”4.22.0″ _module_preset=”default” background_size=”initial” background_position=”top_left” background_repeat=”repeat” max_width=”100%” module_alignment=”center” custom_padding=”||||false|false” use_custom_width=”on” width_unit=”off” custom_width_percent=”100%” global_colors_info=”{}” theme_builder_area=”post_content”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”||||false|false” global_colors_info=”{}” custom_padding__hover=”|||” theme_builder_area=”post_content”][et_pb_text _builder_version=”4.22.0″ _module_preset=”4ff8d2da-4780-4f30-96ef-a867e11f48be” global_colors_info=”{}” theme_builder_area=”post_content”]<\/p>\n On a night dive, every diver should carry a primary light. It is recommended that every diver also carries a backup light. When the primary light fails, switch to your backup light first and then signal your buddy. Use the backup light to safely end the dive. Do not simply continue diving with it.<\/p>\n Making a circular motion with your light signals “OK”. Waving your light slowly up and down is an attention signal but a rapid side to side light wave is considered an emergency attention signal.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row make_equal=”on” _builder_version=”4.22.0″ _module_preset=”default” background_size=”initial” background_position=”top_left” background_repeat=”repeat” max_width=”100%” module_alignment=”center” custom_padding=”||||false|false” use_custom_width=”on” width_unit=”off” custom_width_percent=”100%” global_colors_info=”{}” theme_builder_area=”post_content”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”||||false|false” global_colors_info=”{}” custom_padding__hover=”|||” theme_builder_area=”post_content”][et_pb_text _builder_version=”4.22.0″ _module_preset=”4ff8d2da-4780-4f30-96ef-a867e11f48be” global_colors_info=”{}” theme_builder_area=”post_content”]<\/p>\n Terminology:<\/p>\n Bow \u2013 front of the boat Divers that are prone to seasickness can take seasickness medication before boarding. This medication can be any of several drugs, sold under various brand names. Some seasickness medication may cause drowsiness<\/em><\/strong>. [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”3_5,2_5″ make_equal=”on” _builder_version=”4.22.0″ _module_preset=”default” background_size=”initial” background_position=”top_left” background_repeat=”repeat” max_width=”100%” module_alignment=”center” custom_padding=”||||false|false” use_custom_width=”on” width_unit=”off” custom_width_percent=”100%” global_colors_info=”{}” theme_builder_area=”post_content”][et_pb_column type=”3_5″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”||||false|false” global_colors_info=”{}” custom_padding__hover=”|||” theme_builder_area=”post_content”][et_pb_text _builder_version=”4.16″ _module_preset=”4ff8d2da-4780-4f30-96ef-a867e11f48be” custom_padding=”||5%|” global_colors_info=”{}” theme_builder_area=”post_content”]When diving from a boat, several lines may be used to make the beginning and the end the dive easier. The mooring line<\/strong><\/em> or anchor line<\/strong><\/em> is the line that holds the boat in place. This line can be used to descend or ascend. In rough seas, the mooring line will jerk up and down and a separate descend line<\/strong><\/em> can be used.<\/p>\n A current line<\/strong><\/em> or trail line<\/strong> <\/em>can be trailed behind the boat to assist exiting and entering the water in strong currents. A tag line<\/strong><\/em> or swim line<\/strong><\/em> runs from the mooring line to the stern of the boat and can be used by divers to pull themselves from the entry area to the mooring line or descend line.[\/et_pb_text][\/et_pb_column][et_pb_column type=”2_5″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”|0px||5%” custom_padding_tablet=”” custom_padding_phone=”10%|||0px” custom_padding_last_edited=”on|phone” global_colors_info=”{}” custom_padding__hover=”|||” theme_builder_area=”post_content”][et_pb_image src=”https:\/\/courses.asiascubainstructors.com\/wp-content\/uploads\/2024\/09\/PADI-IDC-theory-boat-diving-lines.jpg” force_fullwidth=”on” align_tablet=”center” align_phone=”” align_last_edited=”on|desktop” _builder_version=”4.16″ _module_preset=”default” animation_style=”fade” animation_delay=”500ms” global_colors_info=”{}” theme_builder_area=”post_content”] [\/et_pb_image][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.22.0″ _module_preset=”default” locked=”off” global_colors_info=”{}” theme_builder_area=”post_content”][et_pb_column type=”4_4″ _builder_version=”4.22.0″ _module_preset=”default” global_colors_info=”{}” theme_builder_area=”post_content”][et_pb_text _builder_version=”4.22.0″ _module_preset=”default” global_colors_info=”{}” theme_builder_area=”post_content”]<\/p>\n
<\/strong><\/span><\/p>\n![\"j-rod\"](\"https:\/\/courses.asiascubainstructors.com\/wp-content\/uploads\/2024\/09\/j-rod-300x300.jpg\")
<\/p>\nCESA<\/h3>\n
Buoyancy check<\/h3>\n
DSMB<\/h3>\n
Drift diving procedures<\/h3>\n
Water movement caused by tides can affect the visibility, depending on the bottom composition. The best time to dive is generally during slack high tide.<\/p>\n
Downcurrents are more likely to occur in areas that are known for having strong currents in general.
When caught in a downcurrent the advice is to stay calm and try to swim away from the wall.<\/p>\nSearch and recovery procedures<\/h3>\n
Circular pattern and jackstay pattern<\/h6>\n
When using a lift bag it should be filled with enough air to make it neutrally buoyant. Slowly bring the object and lift bag to the surface, staying at the side of the lift bag. This allows you to adjust the buoyancy of the liftbag, if needed. Avoid being under the object.<\/p>\nNight diving procedures<\/h3>\n
Boat diving procedures<\/h3>\n
Stern \u2013 back of the boat
Port \u2013 when facing forward, the boat’s left
Starboard \u2013 when facing forward, the boat’s right
Windward \u2013 towards the wind
Leeward \u2013 away from the wind
Head \u2013 toilet
Galley \u2013 kitchen<\/p>\n
If you feel seasick, stay outside in the fresh air. Stay near the stern, in the middle of the boat, that is most stable or near the leeward rail.<\/p>\n