Wave Attenuators FAQ’s

In laboratory tests, the ¼-sized WhisprWave® floating breakwater laboratory units demonstrated a transmission coefficient of 0.6 (dissipated 40% of the energy from waves). In actual “Real World” applications, the full-sized WhisprWave® floating breakwater beach erosion solution has proven to be even more effective. The WhisprWave® floating breakwater erosion control system has been observed to have a transmission coefficient of 0.1 (dissipated 90% of the energy from waves) for coastal waves with periods of 5 seconds or less. The enhanced capabilities of the WhisprWave® erosion control technology in the “Real World” are believed to be the result of the stiffer rubber and stronger anchoring systems of the full sized WhisprWave® products.

The anchoring system is comprised of coastal marine grade time proven chain and anchoring systems attached to the WhisprWave® floating breakwater modules with stainless steel couplings. In coastal marine applications, the anchoring system has demonstrated its capacity to withstand coastal waves in storms with winds up to 80 knots (See anchor loads). If necessary, the WhisprWave® can be engineered to withstand even stronger forces.

Given the flexibility and modularity of the WhisprWave® technology, we need more details about your particular installation in order to provide you with a cost estimate. Please complete the attached information request form and someone will contact you shortly. We sincerely appreciate your interest in our erosion control technologies and maritime port security products.

The expected useful life of the WhisprWave® modules are up to 20 years.

The WhisprWave® is the only marine grade modular erosion control floating breakwater / marine port security barrier designed for ocean deployment. The WhisprWave® is also the only floating breakwater erosion prevention technology capable of dissipating a large variety of shoreline waves with different periods.

Competing floating breakwaters can only dissipate waves with periods under two seconds, the WhisprWave® erosion protection technology has been demonstrated to dissipate waves with periods up to five seconds and is currently being tested on waves up to ten seconds.

The WhisprWave® is also superior at dissipating waves and stopping erosion problems associated with ocean wave activity. While competing products have only been observed to have transmission coefficients of up to 0.8 (dissipating 20% of the energy from waves), the WhisprWave® has been observed to have a transmission coefficient of 0.1 (dissipating 90% of the energy from waves).
Hard permanent structures (rubble breakwaters) are the only competing breakwaters that can match the WhisprWave’s® durability and effectiveness.

These erosion prevention structures, however, have several drawbacks. Most significantly they disrupt the natural ecosystem and are deemed by the regulatory agencies to be environmentally unfriendly. Furthermore, they are significantly more expensive(as much as 400% more then the WhisprWave), reflect erosionary waves instead of dissipating them thus causing further erosion problems at nearby shorelines, and pollute the protected areas by impeding water circulation.

The WhisprWave® floating breakwater erosion protection system can begin installation 45 days after all of the necessary environmental permits have been obtained. Installation time varies depending on the floating breakwater’s structural size and the number of anchors, but typically requires 2 – 3 weeks.

The WhisprWave® buoys can be easily removed and relocated. The WhisprWave® maritime port security barriers and floating breakwaters can also be moved in the water at a slow pace, but are more difficult to physically remove from the water and relocate.

A one year limited warranty is available for all WhisprWave® products.

It is very easy to modify the WhisprWave®. If the initial installation needs to be modified, the WhisprWave® modular structure makes it reasonably easy to adjust.

Obtaining environmental and other regulatory permits is one of the biggest requirements for any WhisprWave® erosion control installation. The fact that the WhisprWave® is a floating breakwater and not a “hard structure” that sits on the ocean’s floor has helped substantially expedite the environmental permitting process. The USACE has determined that the WhisprWave’s floating breakwater technology is easily removable and thus can be permitted as a temporary breakwater. Temporary devices require significantly less permitting requirements than permanent “hard structures” (i.e. rubble breakwaters). Before regulatory agencies will allow a marine system to be installed, they must be convinced that it will have minimal environmental impact. Since the WhisprWave® has been deemed to be environmentally friendly, it is much easier to fulfill this requirement. Permit timing depends on the State agency responsible for the installation, but typically requires 3-9 months to process.

You need to contact your State or local environmental agency, the Secretary of State of the appropriate State, the United States Army Corps of Engineers, the United States Coast Guard, and the local municipalities. WhisprWave® would be happy to assist you in this endeavor.

Maintaining a barrier to ensure its maximum effectiveness may make the life cycle cost of waterside barriers much higher than the initial cost of procurement and installation.  Climatic and other environmental factors can lead to repetitive maintenance and/or maintenance problems.

Surface and subsurface barriers are subject to constant forces from wind, waves, currents and possibly ice and ice flows.  They will also intercept and possibly become entangled in floating debris such as that resulting from upstream floods.  Debris accumulations can add additional stress to barrier components.

Barriers usually consist of a line of individual floating elements connected by cables or other devices. These connections are subject to continuous movement, possibly resulting in fatigue damage and failure of the connections.  Metal components of a barrier system are subject to corrosion.  The detection technologies that comprise the waterside barrier system are also subject to the harshness of weather which can affect performance.

Source: DHS Dams Waterside Barriers Guide

All Floating Security Barriers and Floating Wave Attenuators mooring components, either in use or in storage, must be periodically inspected to determine their current material condition and their future maintenance requirements. The importance of these inspections cannot be overemphasized because the effectiveness of any maintenance program will always depend on how often and how well these checks and services are performed. Inspection plans, therefore, should take into consideration the critical elements of frequency of inspections and the thoroughness, completeness, and quality of work.

There are two types of maintenance:

• In-Service inspections are performed on installed barriers / wave attenuators and moorings
• Out-of-Service inspections are performed on components stored ashore.

There are four basic types of in-service inspections, as follows:

• Annual surface inspections.
• Underwater inspections.
• Riser Sub-Assembly inspections.
• Damage/failure inspections.

ANNUAL SURFACE INSPECTIONS. Shore activities that operate and maintain moorings must inspect the visible portion of each mooring buoy at least once each year. The purpose of this annual surface inspection is to ensure that the barriers or wave attenuators and its topside hardware are in satisfactory condition, and to verify that the barrier / wave attenuator has not been dragged from its proper location.

UNDERWATER INSPECTIONS. The purpose of mooring underwater inspections is to determine the general condition of barrier / wave attenuator and chain assemblies and to verify or update existing as-built drawings and maintenance records. It is recommended that each barrier / wave attenuator mooring will be inspected by divers every 1 to 2 years.

RISER SUB-ASSEMBLY INSPECTION. To avoid disturbing the anchors, a mooring should be lifted only when the riser chain require repair or replacement, or when the barrier or wave attenuator is being completely removed.

MOORING DAMAGE/FAILURE INSPECTIONS. Moorings can be damaged by collisions or dragged out of position by heavy winds or seas. They can also fail because of broken mooring components. An inspection of mooring damage, drag, or failure should be conducted as soon as possible after detection.

IN-SERVICE MAINTENANCE AND REPAIR

In-service maintenance and repair will be limited to the following:

• Minor underwater repairs.
• Minor barrier / wave attenuator and riser assembly repairs.
• Replacement of damaged buoys and/or riser assemblies.
• Minor repairs to cathodic protection systems.

ASHORE INSPECTION AND REFURBISHMENT OF BUOYS

Ashore inspection and refurbishment of barrier / wave attenuator will include visual inspections, repairs, tests, and replacement of damaged components. The purpose of a preliminary inspection is to determine whether the barrier / wave attenuator is in a condition for a further, more detailed inspection and subsequent refurbishment or whether it should be disposed of at this stage.

Source: MO-124 Mooring Maintenance Manual