Introduction

Outdoor recreation positively impacts participants in a variety of ways. Not only does it improve a person’s health and psychological well-being, it fosters a connection with nature and provides a healthy social outlet, increasing a person’s sense of belonging (1-3). Over 60 million Americans participate in motor boating and 24 million go canoeing (3-5). As popular as these activities are, they remain inaccessible or marginally accessible to people with mobility impairments, including over 7.5 million Americans using assistive devices for mobility (6).

One of the most significant barriers to boating for people with limited mobility is transferring to and from the boat. Even basic transfers on solid ground are difficult and lead to many back injuries (7). In their pamphlet on strategies for sailors with disabilities, Disabled Sailors, a long-standing accessible sailing program, states there is a “great need for research into improved transfer board technology.” In prior USDA-sponsored research by BlueSky Designs (BSD), focus group participants identified “getting in and out of the boat” as the top issue when asked what was “most difficult” for them in boating.

In a review of commercially-available lift and transfer technologies, BSD did not find any that would accommodate a watercraft transfer, reduce the physical effort, and qualify as portable. Existing lift and transfer mechanisms for pools or docks are expensive, bulky, or permanent fixtures which attach to either a dock or a larger boat. So-called “portable” devices are on heavily-weighted, wheeled bases, for wheeling around a pool area or a pier; but they weigh far too much to transport in a boat or car. Lower tech options, such as the “LoveHandles” or “Comfort Carrier,” make it easier to conduct a two-person transfer in a sling or seat with handles. However, they do not minimize the lifting required by attendants and do not lessen the risk inherent in stepping into or out of a boat while carrying an awkward load.

Design Objectives

1. To ensure the design meets user operating requirements, preferences, and target specifications
2. To develop and test transfer structures to meet design criteria and specifications
3. To develop and test the safety and stability of supports, legs, suspension, and securement concepts
4. To develop a sliding transfer platform
5. To develop and test traverse mechanisms which facilitate safe passage from one end to the other

Methods

BSD's approach incorporated universal design principles, consumer input, and an iterative design process to achieve its objectives. After an initial design cycle based on input and feedback from previous work, boaters participated in focus groups. Participants completed questionnaires to describe their personal boating and transfer preferences. Following a demonstration of prototypes and design concepts, participants completed feedback forms. Where applicable, a five-point Likert scale was used.

Subjects (nfemale=11, nmale=10, ages 21 to 79 years) came from a variety of ability levels and backgrounds. Consumers were recruited from adaptive boating programs and response to newsletter articles. All reported more than 10 years boating experience and were divided into five categories depending on their boating background and level of involvement.

1. Independent boaters (n=4) include boaters with disabilities who transfer independently,
2. Assisted boaters (n=4) include boaters requiring assistance getting into and out of boats,
3. Older boaters (n=2) include those over the age of 65,
4. Family/Friends/PCA boaters (n=7) include able-bodied boaters who boat with friends or family members with disabilities, and
5. Program staff (n=4) include staff from boating programs for people with disabilities.

Design Concepts

BSD developed a variety of transfer structures – systems to enable transfers between a dock or beach and a small boat – as well as components to accommodate seating, disturbances from waves, or effort reduction. An adjustable dock and rocking boat were developed to simulate the marine environment and allow indoor testing. The two most promising transfer structures were the Frame and Fabric Chute (FFC) (Figure 1) and the Rail System (Figure 2). The FFC was designed to be used and carried on small boats, such as canoes and kayaks and can be used on larger craft. The FFC has a level transfer platform with four folding legs for stability. A hinged section extends from the transfer platform and can be inclined or declined to reach the watercraft. Several boat-end supports were fabricated and tested, including folding height-adjustable legs, a clamping talon, a landing pad, and a kayak attachment. The whole unit weighs approximately 15.5 pounds and folds to about 16x24x12 inches.

The Rail System is a more substantial structure with a wider array of options for transferring individuals who require more assistance. Two rails span support frames on either end, incorporating two height adjustable legs. The feet are rounded to accommodate movement of the boat in waves. The rails are spaced 16” apart. An optional third pole is 12” higher and offset 6” wider. These arrangements allowed BSD to test transfer platforms and seats that rode on the parallel bars, as well as seats oriented sideways, with the seat back supported by the upper rail. The upper rail could also be used as a grab bar. In addition, a fabric surface can be attached to the Rail System to facilitate seated or recumbent transfers.

Seating system concepts included a Rigid Seat, Bead Seat, and Rocker Seat. The Rigid Seat featured tilt adjustment and modular back and lateral supports to allow the rider to sit in line or perpendicular to the transfer path. The sling-style Bead Seat featured a conformable seat cushion for pressure relief and pelvic leveling. The Rocker Seat included a contoured plastic seat with curved attachment hardware and swivel bracket to allow for tilt adjustment. Both the Bead Seat and Rocker Seat had modular trunk supports available.

Wave attenuation supports were developed to mitigate the instability produced by waves, swells, and shifting weight distribution. The Air Bladder provided a fluid joint between the transfer path and the watercraft and allowed the watercraft to rock side to side and pitch fore and aft while maintaining a relatively stable transfer path. The Pan and Bowl consisted of a ball and socket that also allowed the watercraft to rock side to side and pitch fore and aft with minimal disturbance of the transfer path. The Foam Dashpot, constructed of two densities of foam in a conical configuration, did not perform well. Mechanical testing showed that rounded feet on the legs served as a simple and effective solution.

Traverse mechanism prototypes were developed to facilitate safe and easy passage from one end to the other. The most promising traverse mechanism, the Ratcheting Pulley (Figure 2c), reduced force requirements by 58% and 70% with two and four pulleys, respectively. An able-bodied tester was unable to lift himself up inclinations greater than 5° without the pulley system yet was able to do so at 20° with the Ratcheting Pulley. Hand rails were developed for both the FFC and Rail System to provide a grab bar to assist in moving along the path. Speed Bumps in both designs created detents that provided resting points, kept the user from sliding back down, and facilitated a controlled descent.

Results

User preferences varied by consumer group. Safety was the most important concern across groups, followed by ease of transfer, stability, and amount of physical effort, which varied by consumer group. Other design priorities included ease of use and portability. When asked about conditions in which they go boating, nearly everyone expected there may be mild waves or calm conditions. Participants generally favored a wave attenuation mechanism. Participants generally preferred some degree of mechanical assist, starting with the provision of handrails, though 75% of the participants in the Independent group reported that they would likely use a watercraft transfer device without a seat or handrails.

A vast majority of participants preferred the FFC and Rail System over other concepts presented (Figure 3). Those in the Independent group questioned the stability of the FFC but liked its portability and light weight. Participants liked the stability of the Rail System but questioned its portability, and those in the Family/Friend/ PCA group liked how the top bar could be used as a grab bar.

Participants heavily favored the Bead Seat and Rigid Seat. Participants from every group liked the modularity of the Rigid Seat and how it could suit a variety of people, but they mentioned it looked bulky and were concerned about the risk of losing parts. Alternatively, participants liked the simplicity of the Bead Seat; but they noted it did not provide as much trunk support as the Rigid Seat. While the ratings were not as good for other seat concepts, participants liked the option of feet containment.

Of the mechanical assist options, the Ratcheting Pulley, Lever Friction Brake, Speed Bumps, and Spring Cam Cleats received positive ratings. Participants in the Independent group liked the Speed Bump concept for its simplicity. One person in the Assisted group was very enthusiastic about redundant braking. While she would not have been able to move herself with the Ratcheting Pulley, she was supportive of having a brake next to her in the event she wanted or needed to stop herself.

Discussion

A couple unexpected outcomes occurred during the course of development. We had presumed maintaining dignity would be high on the priority list for older boaters. However, older boaters we interviewed did not place dignity as high as safety, ease of transfer, stability, physical effort, and independence of use. Also, we did not expect the watercraft transfer device concepts to be as stable as they were without dedicated wave attenuation mechanisms. Simply providing a wide base of support and ensuring that the supports in the boat were near its center seemed to provide satisfactory stability. Rounded feet also helped. This has the added benefit of reducing the cost of the device.

Results answered key questions with respect to requirements and specifications for a portable watercraft transfer device and produced technically feasible concepts that consumers could see themselves using. The highly positive responses to both the FFC and the Rail System suggest that future research and development be focused on these two approaches. Some of the desired features that the FFC achieved were its portability, simplicity, lightweight, and compactness. Future development for the Rail System would address material selection, joint design, and the rail configuration. The participants who anticipated using the watercraft transfer device in a dedicated spot, such as those in accessible boating programs or participants with lake cabins, valued stability and ease of use more than portability. This market segment may lead to a third approach with a rail system that is robust, economical, and minimally portable, perhaps secured to a dock or boat. Additional research is warranted in the development of a watercraft transfer system as it addresses a significant barrier to safe and independent recreation.