Search and Recovery

Knowledge Review - Part 1

A recreational search and recovery diver:

Six potential hazards of search and recovery diving include:

Five general steps in planning a search and recovery dive are:

Use an expanded square search pattern or a U search patter when:

Use a circular rope search pattern when:

Execute a circular roper search pattern by:

You should never use your BCD for lifting objects because it could result in a runaway ascent.

The use of a lift bag becomes mandatory with anything over 10 pounds.

Three reasons why commercially-made lift bags should be used for recovering underwater objects:

Procedure for controlling, rigging, and lifting an object using a lift bag:

secure a marker buoy and the lift bag to the object
check rigging
inflate the bag slowly in small bursts, pulling up between bursts, until it hovers
swim the bag and object horizontally (if necessary)
begin swimming up slowly with the bag
escort the bag venting to control ascent, or allow it to ascend independently

Alternate second stage or an accessory inflater are the only air sources you should use for filling a lift bag.

Procedure for a jackstay search pattern:

use when searching for small object in large, relatively flat area with moderate current
establish baseline along search area
both divers start at edge of search area at one end of base line
Diver 1 swims search rope out perpendicular to baseline, searching
Diver 2 remains in place anchoring other end
Diver 1 reaches end of line and pulls it tight, then takes the end and swims toward unsearched area a short distance based on visibility and required overlap
Diver 1 anchors the end and swims back along the search rope back to Diver 2, searching
reunited, both divers move forward until search rope is perpendicular with baseline
repeat

Procedure for snorkeler led search pattern:

use with one or more divers over a relatively large pattern looking for a relatively large object
establish search area with anchored buoys or landmarks at four corners
snorkeler swims the pattern
divers swim in a V pattern with leader holding line

Procedure for semicircular search pattern:

use over bottoms that are flat and obstruction free and in current you can swim against
select a compass heading that takes search in straight line through search area
diver 1 holds search line
diver 2 swims with other end along the determined compass heading until it’s taut
if divers cannot see each other, then make search line shorter
diver 2 becomes anchor diver
diver 1 becomes search diver
search diver swims half circle until realigning with the heading
anchor diver watches and signals when search diver reaches that point
divers switch roles
when they reach end of search area then searching diver makes full circle, switching direction
if object is not found, then establish another line overlapping original one

Procedure for shore walk search pattern:

use when searching a large area along shore, with one or many divers, and a tender on shore
tender holds search line and walks along shore
divers start at deepest point away from shore
divers hold line taut while swimming and search perpendicular from shore
when divers they reach end of search area, tender signals and takes up line
divers reverse direction
repeat until at shallow depth

Bottom topography and water movement can affect a search by:

Professional search and recovery differs from recreational in that:

Pinpoint a fix on a submerged object while at the surface over it by:

Relocate an object using a known fix by:

Three commonly used knots for search and recovery are:

Prepare for tying knots underwater by: