Incident Report: Flooding Aboard NOAA Survey Launch

This incident report is submitted pursuant to Section 17.05 of the NOAA Small Boat Standards & Procedures Manual. The section states that lessons learned from incidents and near misses, as well as suggested corrective actions, will the distributed through the small boat community.

Thirty minutes after a routine launch deployment from the NOAA Ship Fairweather, the launch crew noticed water accumulating in the cabin bilge. The water intrusion was investigated, and found to be entering via the through-hull penetration normally used for the Side Scan Sonar cable.

When in service, the Side Scan Sonar unit is mounted on the hull of the launch, while the computer unit is located inside the launch cabin. The computer unit and the sonar unit communicate through a 1/8^th inch diameter cable, which penetrates the hull using a specially fitted cable pass-through. When the Side Scan Sonar is out of service the sonar unit is removed from the hull, and the through-hull penetration is sealed using a solid dummy plug.

On investigation, the launch crew observed that the fitted cable pass-through was in place, but the sonar unit was not mounted and the cable was not in place. The launch immediately returned to Fairweather and was lifted out of the water. After being lifted out, 6 gallons of sea water was pumped from the bilge.

Findings

Two weeks prior the incident the Side Scan Sonar had been removed from the launch, but the fitted cable pass-through was returned into service instead of being replaced with the solid dummy plug.  The launch was not used during the intervening 2 weeks, and the time between the equipment being removed and the launch deployed caused a failure in pass-down communication.

Corrective Actions

Both the OMAO Safety Management Branch and the OMAO Small Boat Safety Board reviewed the incident, and suggest corrective actions.

1. Checklists are recommended for thru-hull penetrations, similar to lock out/ tag out requirements to ensure watertight integrity is reestablished before launching. 
2. Complete shakedown immediately following repairs/work before considering complete, and/or communicate the most recent work before launching to ensure work area is not forgotten as a hazard that isn’t assessed when redeploying for the first time.