PSS 10.6 Parallel Line Search Pattern

Purpose

To provide guidelines regarding parallel line search patterns.

Policy

Surf Life Saving NSW (SLSNSW) provides the following guidelines to assist personnel in effectively performing their duties.

Procedure

Parallel line search patterns are used when the area of probability is large and the location of craft or person in distress is not well established. The search legs used are parallel to the major axis of the search area. This search pattern can be carried out by single or multiple vessels.

The parallel line search pattern is best used in rectangular or square areas. It is a very suitable pattern for a search conducted over water. The search vessel/s proceeds from one corner of the search area maintaining parallel tracks. Successive tracks are maintained parallel to each other and one track spacing apart.

This type of search may be carried out by one aircraft or by several aircraft following parallel tracks or each searching smaller rectangular areas separately.

This search pattern provides uniform coverage and should be utilised only when operating in the open ocean. Search and rescue crews should follow the following steps when utilising this search pattern for single vessels:

1. The search pattern shall begin at one corner of the search area.
2. Crews shall take a visual reference or drop a buoy and anchor as a surface marker. This will then provide a continuous reference point during the search.
3. The search pattern should begin so that there is a continuous overlap of vision throughout the search.
4. Crews shall ensure that successive tracks are maintained parallel to each other and are one track space apart.

Parallel line searches utilising more than one vessel should follow the same steps as one vessel operations but include the following considerations:

1. When operating within a relatively small area of probability (e.g. a beach 500 metres or less in length) each craft shall be designated a specific starting point in the search area in line with each vessel and shall be one track spacing apart.
2. When operating within a relatively large area of probability (e.g. a beach greater than 500 metres in length) each craft shall be designated a specific section of the search area based on distance with a specific overlap distance incorporated e.g. each vessel is designated a starting point 300 metres apart with an overlapping distance of 50 metres.