USGS Home
Contact USGS
Search USGS

U.S. GEOLOGICAL SURVEY
Open-File Report 2008-1020

Needs Assessment and Scoping Study for Sinking Ships as Diving Sites in Puget Sound

Prepared for: Washington Department of Fish and Wildlife Olympia, Washington

By Steve Rubin, Eric Grossman, Lynne Koontz, Anthony Paulson, Natalie Sexton, and Reg Reisenbichler

Executive Summary

There is growing interest in starting a program to sink one or more large, steel ships in Puget Sound to create underwater dive sites, thereby attracting divers to Washington State with attendant economic benefits. The State legislature reviewed this possibility during the 2006 session and directed several State agencies to undertake a preliminary scoping study of the feasibility. The Washington Department of Fish and Wildlife (lead State agency) in turn asked the U.S. Geological Survey to conduct the study.

The objectives of the scoping study are to design a feasibility study and estimate the cost to conduct such a study. Specifically, the scoping study assembles the questions that a feasibility study should address, develops approaches or tasks to address each question, and estimates the cost associated with each approach or task. The main objective for the feasibility study would be to provide sufficient information for the legislature to decide whether to go forward with actual ship sinking. Specifically, the objectives of the feasibility study would be to (1) estimate the costs (initial and ongoing) of sinking ships, (2) estimate the economic benefits that would be derived, (3) identify political and community stakeholders and gauge their support or opposition, and (4) develop detailed information about environmental (physical, water quality, biological) impacts.

Initial and ongoing costs of ship sinking include ship selection, acquisition, preparation, and deployment; site selection; permitting; liability coverage; developing necessary infrastructure; maintenance; and monitoring. Contaminant removal is a key element of ship preparation, and ease of contaminant removal is an important ship selection criterion. Contaminants are retained in Puget Sound due to basin morphology and current circulation patterns, and sediments and biota show elevated levels of contaminants. Major initiatives are underway to prevent contaminants from entering the Sound and to clean up those that are already present. For these reasons thorough contaminant removal is imperative. The Environmental Protection Agency and the Maritime Administration (MARAD) recently established best management practices (BMPs) for contaminant removal from ships destined for sinking. Whether these BMPs are sufficient for Puget Sound needs to be evaluated. There is also growing concern about polybrominated diphenyl esters (PBDEs) and other “emerging contaminants”, so called because their effects are less well known than those of older contaminants such as polychlorinated biphenyls (PCBs). BMPs have not yet been established for emerging contaminants. PCBs and PBDEs bio-accumulate and are found at high levels in southern resident killer whales which spend much of their time in Puget Sound and are listed as endangered under the Endangered Species Act. Contaminants are considered a major threat to this whale population. The feasibility study needs to estimate the inventory of contaminants on each of the candidate vessel classes, which for emerging contaminants will likely require onboard sampling of ship materials, and determine the feasibility and cost of contaminant removal.

The largest navy ships (e.g., aircraft carriers) are hard to clean of contaminants which may make these ships poor choices. Furthermore, total cost (acquisition to sinking) is directly proportional to ship weight, making large ships expensive. Ships may be available from the U.S. Navy or MARAD; however, subsidies currently offered by these agencies for cleaning and transport cover only a small fraction of the costs. Two types and sizes of ships have been suggested as potentially good choices for Puget Sound. The first is Washington State ferries (~250 feet long; ~2,000 tons). They have an open structure that may allow for easy cleaning, were rebuilt recently which may have removed some contaminants, and have a known service history which should facilitate contaminant assessment. The second is medium sized destroyers as have been sunk in the Strait of Georgia (~350 feet; ~3,000 tons). However, the smallest destroyers currently available from the Navy or MARAD may be ~500 feet long (3000-6000 tons).

A number of factors must be considered in selecting a site. Physical characteristics must ensure ship stability and provide safe and desirable diving conditions. Navigation lanes and sensitive species and habitats must be avoided. We propose a two stage approach for locating suitable sites and confirming their suitability. First, use existing data to construct a Puget Sound-wide map to roughly identify areas that may be physically suitable and don’t conflict with navigation or sensitive species or habitats. Note that existing data, with the possible exception of depth, lack sufficient resolution at the scale needed to ensure suitability for ship sinking. Second, conduct field surveys at five of the potentially suitable sites, selected to provide some geographic variability, to confirm whether sites identified from the Sound-wide map meet requirements of substrate type, seafloor structural integrity, water clarity, current speeds, and biological community.

Potential environmental impacts (other than contaminants which are addressed above) include scouring or deposition, increased turbidity, harm to sensitive or harvested species or to sensitive habitats or aquatic communities (e.g., eel grass beds), loss of the benthic community at the sinking site (i.e., under the ship), changes in ecological processes, promotion of invasive species, and cumulative effects of multiple ships. Ship colonizers might compete with or prey upon organisms in the area surrounding the ship or passing by the ship, thus altering the food web. Sunken ships may attract organisms away from hard substrate habitat in surrounding areas which would be especially problematic if attraction resulted in reduced survival, a circumstance that could result from increased harvest rates if harvest were allowed. A potential benefit of ship sinking might be promotion of sensitive species such as rockfish. It might be possible to design ship sinking to maximize any such benefit if it were identified as a secondary objective and did not conflict with creation of the dive site or the well being of other sensitive species.

Important considerations in evaluating support or opposition to ship sinking are the regulatory framework for sinking ships; the policies, structures, and incentives that will likely drive the decision process; the identity of stakeholders; and the perceptions, attitudes, and preferences of nearby communities as well as key stakeholders. This report proposes comparative studies of similar ship sinking programs in other areas, focus groups to qualitatively explore attitudes and perceptions of divers and other stakeholders, and surveys of divers and local community members to quantitatively assess attitudes and perceptions.

Because the costs associated with sinking ships to create dive attractions can be substantial, the economic benefits must be examined to determine if the project would be an advisable investment. To estimate anticipated economic benefits it is necessary to estimate the number of divers and average spending per diver currently (pre-deployment) and after deployment. Sampling of dive charter logbooks, and on-water sampling to determine the ratio of charter to non-charter divers, is proposed to estimate the current number of divers. Surveys of divers are proposed to estimate the number of future divers and the average spending per diver currently and in the future. The best (and most expensive) option is to survey divers nation-wide as well as in Washington. This may be the only way to estimate the post-deployment influx of non-residents into Washington. Surveys will also allow evaluation of how economic benefit varies among regions within Puget Sound. Once the gross economic benefit is determined (i.e., anticipated additional funds attributable to ship sinking), the net economic benefit can be determined by subtracting out anticipated project costs, including costs of new infrastructure.

We present three funding options for the feasibility study: “full” with consideration of two ship types (ferries and destroyers), “minimal for two ship types”, and “minimal for ferries only”. The ferries-only option is included to provide a cheaper alternative and because ferries may offer greater ease of cleaning than destroyers. Both minimal options rely mostly on existing data whereas the full option includes significant development of new data for tasks associated with siting, evaluation of community support or opposition, and estimation of economic benefits. The purpose for these new data is to validate, refine, or provide critical information for making predictions and conclusions. The full option will provide the most reliable assessment of feasibility across Puget Sound. The minimal options include field sampling at only one site rather than at five sites, which seems most appropriate if that one site has been selected as the desired location for sinking a ship, subject to final field verification. The estimated total cost of the feasibility study is $2.8 million for the full level, $1.4 million for the minimal level with two ship types, and $1.2 million for the minimal level with ferries only, assuming an overhead rate of 100%. Overhead rates vary among potential contractors from less than 50% to well over 100%.

Other funding levels are possible. We described the tasks that we think should be included in a feasibility study, along with a cost estimate for each task and information on how we derived the estimate. From this information the reader may wish to adjust, eliminate, or even add tasks, or to adjust cost estimates to create other alternatives for study intensity or cost.

The feasibility study could be conducted in stages. Contaminant issues might be evaluated first because of their overriding importance. Only if thorough cleaning were found to be feasible for ships of interest would other components of the study proceed. Alternatively, economic benefits could be evaluated first, and the other components of the study proceed only if economic projections were favorable. A sequential strategy would obviously save money if thorough cleaning isn’t feasible or if economic projections are disappointing; however, the strategy would extend the duration of the study if neither of these factors preclude ship sinking. If all feasibility components were conducted concurrently, the duration of the study should be approximately 18-24 months. We recommend the sequential strategy if cost efficiency is more important than minimizing the time required to complete the feasibility study. We also recommend choosing the full budget option for evaluating economic benefits because of the increased accuracy of predictions relative to those from the minimal options.

Contents

Executive Summary
Introduction
Scoping Study Methods and Format
Feasibility Study Questions, Tasks, and Costs
Feasibility Study Budget
Discussion
Recommendations
Acknowledgments
References Cited
Appendixes

This report is available online in Portable Document Format (PDF). If you do not have the Adobe Reader, it is available for free download from Adobe Systems Incorporated.

Download the report (PDF, 322 KB)

Document Accessibility: Adobe Systems Incorporated has information about PDFs and the visually impaired. This information provides tools to help make PDF files accessible. These tools convert Adobe PDF documents into HTML or ASCII text, which then can be read by a number of common screen-reading programs that synthesize text as audible speech. In addition, an accessible version of Adobe Reader 8.0 for Windows (English only), which contains support for screen readers, is available. These tools and the accessible reader may be obtained free from Adobe at Adobe Access.

Send questions or comments about this report to the author, Steve Rubin, (206) 526-6282 ext. 324.