This document outlines the standard operating procedure for divers to perform hydro-vacuuming at the Newport Aquarium. It details: 1) Coordinating with engineering staff, using designated equipment, and priming the pump by filling hoses with water before starting. 2) Using the siphon tube to suck gravel and debris up from the exhibit substrate while hydro-vacuuming assigned areas. 3) Disassembling, cleaning, and storing the equipment when finished.

1. NEWPORT AQUARIUM
Operating & Maintenance Procedures
Revision Date:
09/2/14
Page:
1 of 2
Procedure: Diver Hydro-Vacuuming Issued By:
HUSB-DIVE
Approved By:
Dive Safety Com.
Purpose: To identify the standard for performing hydro-vacuuming an exhibit while on SCUBA.
Scope: This procedure applies to all diving activities conducted in exhibits at the Newport
Aquarium.
I. DEFINITIONS
a. Hydro-vacuuming refers to the method of cleaning exhibit substrate by use of a pump, hoses,
and siphon tube.
II. GENERAL PROCEDURE
a. Dive staff must coordinate hydro-vacuuming with Engineering Life Support (LS) staff.
b. Stand-by diver will alert Engineering LS when the pump is started and when it is finished.
c. Divers will use only the hydro-vac equipment intended for use in that exhibit.
d. Only those electrical outlets marked with dive flag stickers may be used for the pump.
III. EQUIPMENT
a. Hydro-vac equipment includes:
1) Pump
2) White intake hose
3) Blue output hose
4) Siphon tube
b. Divers will assemble the hydro-vac equipment topside prior to entry.
1) Unwind all hoses to remove loops. The straighter the hose, the better the flow.
2) Connect intake hose to inlet at front of pump.
3) Run the output hose through the pump handle, then connect it to the outlet on the top of
the pump. This will give the hose support and prevent crimping.
4) Feed the intake hose out into the water, trying to keep it as straight as possible.
5) Put the open end of the ouput hose into the proper floor drain.
c. Divers will prime the pump.
1) Hold the open end of the intake hose at or slightly above the level of the pump.
2) Using a 5-gallon bucket, pour exhibit water into the pump via the strainer basket. This
will fill the hose and prime the pump. It takes approximately two (2) buckets to prime the
pump.
3) When the system is full of water, screw down the pump lid securely, verifying that the
large o-ring is in place and the pump is plugged in to the proper outlet.
4) Place the open end of the intake hose underwater, and immediately turn on the pump.
5) Watch for water in the strainer lid and movement in the dump hose to indicate that the
pump is moving water.
6) When the pump is running at full flow, affix the siphon tube to the hose, taking care to
keep everything underwater.
7) Contact Engineering LS that the hydro has begun.
d. Divers will hydro-vac the assigned area of the exhibit.
1) The strenghth of suction can be controlled by opening and closing your hand over the
holes in the neck of the siphon tube.
2) Drive the siphon tube deep into the exhibit substrate, keeping your hand over the holes
and sucking the gravel about 1/3 of the way up the tube. There is a point of no return at
which the gravel will get sucked up into the pump. Don’t do that.
3) Release your hand from the holes, lessening the suction, and lift the tube out of the
substrate, allowing it to fall back to the bottom while the schmutz goes up the tube.
4) Repeat.
e. When hydro-vacuuming is finished, divers can alert the standby diver, who can then turn off the
pump and contact Engineering LS.
f. Divers will disassemble and clean the pump
1) Disconnect and drain hoses.

2. NEWPORT AQUARIUM
Operating & Maintenance Procedures
Revision Date:
09/2/14
Page:
2 of 2
Procedure: Diver Hydro-Vacuuming Issued By:
HUSB-DIVE
Approved By:
Dive Safety Com.
2) Empty and clean pump strainer basket.
3) Rinse pump with fresh water, taking care to avoid pump motor.
4) Stow pump and its components and squeegee the floors.
IV. DOCUMENTATION
a. Employees shall sign off that they have read and understand the SOP for Diver Hydro-
Vacuuming.
b. Sign-offs shall be kept in the Red Binder.