A Uniform Minimum Safe Diving Depth for Swimming Facilities

2009 ◽  
pp. 77-77-8
Author(s):  
RR Gilbert
Keyword(s):  
Diving Depth

Allometry of diving capacity in air-breathing vertebrates

1997 ◽  
Vol 75 (3) ◽  
pp. 339-358 ◽  
Author(s):  
Jason F. Schreer ◽  
Kit M. Kovacs
Keyword(s):  
Body Mass ◽  
Marine Mammals ◽  
Strong Relationship ◽  
Allometric Relationship ◽  
Air Breathing ◽  
Diving Depth ◽  
Maximum Duration ◽  
Phocid Seals ◽  
Bird Group ◽  
Taxonomic Groups

Maximum diving depths and durations were examined in relation to body mass for birds, marine mammals, and marine turtles. There were strong allometric relationships between these parameters (log10 transformed) among air-breathing vertebrates (r = 0.71, n = 111 for depth; r = 0.84, n = 121 for duration), although there was considerable scatter around the regression lines. Many of the smaller taxonomic groups also had a strong allometric relationship between diving capacity (maximum depth and duration) and body mass. Notable exceptions were mysticete cetaceans and diving/flying birds, which displayed no relationship between maximum diving depth and body mass, and otariid seals, which showed no relationship between maximum diving depth or duration and body mass. Within the diving/flying bird group, only alcids showed a significant relationship (r = 0.81, n = 9 for depth). The diving capacities of penguins had the highest correlations with body mass (r = 0.81, n = 11 for depth; r = 0.93, n = 9 for duration), followed by those of odontocete cetaceans (r = 0.75, n = 21 for depth; r = 0.84, n = 22 for duration) and phocid seals (r = 0.70, n = 15 for depth; r = 0.59, n = 16 for duration). Mysticete cetaceans showed a strong relationship between maximum duration and body mass (r = 0.84, n = 9). Comparisons across the various groups indicated that alcids, penguins, and phocids are all exceptional divers relative to their masses and that mysticete cetaceans dive to shallower depths and for shorter periods than would be predicted from their size. Differences among groups, as well as the lack of relationships within some groups, could often be explained by factors such as the various ecological feeding niches these groups exploit, or by variations in the methods used to record their behavior.

Finite element analysis and design optimization of a non-circular sandwich composite deep submarine pressure hull

2020 ◽  
Vol 62 (10) ◽  
pp. 1025-1032
Author(s):  
Mahmoud Helal ◽  
Elsayed Fathallah
Keyword(s):  
Finite Element Analysis ◽  
Structural Design ◽  
Parametric Design ◽  
Failure Criteria ◽  
Sensitivity Analyses ◽  
Sandwich Composite ◽  
Element Analysis ◽  
Analysis And Design ◽  
Diving Depth ◽  
Ansys Parametric Design Language

Abstract Diving depth is the criteria for designing the submarine pressure hull meant to achieve a definite collapse depth. In this study, a methodology to optimize a sandwich composite deep pressure hull is presented. Buoyancy factor (BF) minimization is considered as an objective function. The optimization process is achieved by ANSYS parametric design language (APDL). Composites failure criteria and structural stability are considered as constraints. Additionally, sensitivity analyses were conducted to analyze the effects of geometric parameters on optimal structural design. The results showed that, the utilization of a sandwich composite pressure hull for a deep submarine at extreme depths is not safe. Additionally, the results propose that the submarine designed should be able to operate at a maximum diving depth of up to 7500 m.

Depth Profiling Investigation of Seawater Using Combined Multi-Optical Spectrometry

2020 ◽  
Vol 74 (5) ◽  
pp. 563-570 ◽  
Author(s):  
Wangquan Ye ◽  
Jinjia Guo ◽  
Nan Li ◽  
Fujun Qi ◽  
Kai Cheng ◽  
...  
Keyword(s):  
Deep Sea ◽  
Depth Profiling ◽  
Deep Ocean ◽  
Euphotic Zone ◽  
Depth Resolution ◽  
Remotely Operated Vehicle ◽  
Sea Trial ◽  
Depth Profiles ◽  
Diving Depth ◽  
Optical Spectrometry

Depth profiling investigation plays an important role in studying the dynamic processes of the ocean. In this paper, a newly developed hyphenated underwater system based on multi-optical spectrometry is introduced and used to measure seawater spectra at different depths with the aid of a remotely operated vehicle (ROV). The hyphenated system consists of two independent compact deep-sea spectral instruments, a deep ocean compact autonomous Raman spectrometer and a compact underwater laser-induced breakdown spectroscopy system for sea applications (LIBSea). The former was used to take both Raman scattering and fluorescence of seawater, and the LIBS signal could be recorded with the LIBSea. The first sea trial of the developed system was taken place in the Bismarck Sea, Papua New Guinea, in June 2015. Over 4000 multi-optical spectra had been captured up to the diving depth about 1800 m at maximum. The depth profiles of some ocean parameters were extracted from the captured joint Raman–fluorescence and LIBS spectra with a depth resolution of 1 m. The concentrations of [Formula: see text] and the water temperatures were measured using Raman spectra. The fluorescence intensities from both colored dissolved organic matter (CDOM) and chlorophyll were found to be varied in the euphotic zone. With LIBS spectra, the depth profiles of metallic elements were also obtained. The normalized intensity of atomic line Ca(I) extracted from LIBS spectra raised around the depth of 1600 m, similar to the depth profile of CDOM. This phenomenon might be caused by the nonbuoyant hydrothermal plumes. It is worth mentioning that this is the first time Raman and LIBS spectroscopy have been applied simultaneously to the deep-sea in situ investigations.

scholarly journals Features of glossopharyngeal breathing in breath-hold divers

2006 ◽  
Vol 101 (3) ◽  
pp. 799-801 ◽  
Author(s):  
Leigh M. Seccombe ◽  
Peter G. Rogers ◽  
Nghi Mai ◽  
Chris K. Wong ◽  
Leonard Kritharides ◽  
...  
Keyword(s):  
Vital Capacity ◽  
Total Lung Capacity ◽  
Breath Hold ◽  
Lung Capacity ◽  
Diving Depth ◽  
Highly Correlated ◽  
Pressure Changes ◽  
Air Compression ◽  
The Relationship ◽  
Measured Volume

One technique employed by competitive breath-hold divers to increase diving depth is to hyperinflate the lungs with glossopharyngeal breathing (GPB). Our aim was to assess the relationship between measured volume and pressure changes due to GPB. Seven healthy male breath-hold divers, age 33 ( 8 ) [mean (SD)] years were recruited. Subjects performed baseline body plethysmography (TLCPRE). Plethysmography and mouth relaxation pressure were recorded immediately following a maximal GPB maneuver at total lung capacity (TLC) (TLCGPB) and within 5 min after the final GPB maneuver (TLCPOST). Mean TLC increased from TLCPRE to TLCGPB by 1.95 (0.66) liters and vital capacity (VC) by 1.92 (0.56) liters ( P < 0.0001), with no change in residual volume. There was an increase in TLCPOST compared with TLCPRE of 0.16 liters (0.14) ( P < 0.02). Mean mouth relaxation pressure at TLCGPB was 65 (19) cmH2O and was highly correlated with the percent increase in TLC ( R = 0.96). Breath-hold divers achieve substantial increases in measured lung volumes using GPB primarily from increasing VC. Approximately one-third of the additional air was accommodated by air compression.

Resilient guaranteed cost diving depth control of AUV

2010 ◽  
Author(s):  
Yuesheng Luo ◽  
Shiwei Li ◽  
Xu Qi ◽  
Xingyan Zhang ◽  
Xiuping Wen ◽  
...  
Keyword(s):  
Diving Depth ◽  
Guaranteed Cost ◽  
Depth Control

scholarly journals It is time to move: linking flight and foraging behaviour in a diving bird

2007 ◽  
Vol 3 (4) ◽  
pp. 357-359 ◽  
Author(s):  
David Pelletier ◽  
Magella Guillemette ◽  
Jean-Marc Grandbois ◽  
Patrick J Butler
Keyword(s):  
Permutation Test ◽  
Dynamic Environment ◽  
The Body ◽  
Somateria Mollissima ◽  
Data Logger ◽  
Body Angle ◽  
Diving Depth ◽  
Adaptive Value ◽  
Duck Species ◽  
Diving Bird

Although the adaptive value of flight may seem obvious, it is the most difficult behaviour of birds to monitor. Here, we describe a technique to quantify the frequency and the duration of flights over several months by implanting a data logger that records heart rate ( f H ), hydrostatic pressure (diving depth) and the body angle of a large sea duck species, the common eider ( Somateria mollissima ). According to the mean f H recorded during flight and the parameters recorded to identify the f H flight signature, we were able to identify all flights performed by 13 individuals during eight months. We cumulated local flight time (outside migrations) and found that activity occurs primarily during dawn and morning and that flying activities are strongly related to diving activities (Pearson's r =0.88, permutation test p <0.001). This relationship was interpreted as a consequence of living in a dynamic environment where sea currents move the ducks away from the food patches. We believe that the technique described here will open new avenues of investigation in the adaptive value of flight.

Habitat selection by common eiders in winter and its interaction with flock size

1993 ◽  
Vol 71 (6) ◽  
pp. 1259-1266 ◽  
Author(s):  
Magella Guillemette ◽  
John H. Himmelman ◽  
Cyrille Barette ◽  
Austin Reed
Keyword(s):  
Habitat Selection ◽  
Shallow Water ◽  
Prey Density ◽  
Sea Urchins ◽  
Day Length ◽  
Antipredator Behaviour ◽  
Somateria Mollissima ◽  
Flock Size ◽  
Eastern Canada ◽  
Diving Depth

We studied habitat selection in relation to prey density and water depth in the common eider, Somateria mollissima L., wintering in the Gulf of St. Lawrence, eastern Canada. In this region, eiders are confronted with low temperatures, ice cover, and reduced day length. We predicted that they should select feeding habitats characterized by high prey density and shallow water to minimize the time and energy spent while diving. About 1000 flocks were localized by triangulation on our study site (20.5 km2). We inferred the diving depth and the habitat being used from the position of eiders on bathymetric and community maps. The highest density of prey occurred in shallow water reefs where there were patches of blue mussels, Mytilus edulis L., and green sea urchins, Strongylocentrotus droebachienensis (Müller). Despite the fact that eiders can dive to depths as great as 42 m to feed, they strongly aggregate in shallow water, and their distribution closely coincides with the highest density of prey. The degree of selection for the reef habitat varies with seasonal variations in the size of flocks and in the total number of eiders present. Although flocking as an antipredator behaviour cannot be rejected, we interpret the high degree of flocking by eiders in our study area as a strategy to facilitate feeding in winter.

Status of the Atlas Elektronik’s Modular AUV Family

2006 ◽  
Author(s):  
Willi Hornfeld
Keyword(s):  
Autonomous Underwater Vehicles ◽  
Leading Edge ◽  
Cost Effective ◽  
Control Site ◽  
Single Type ◽  
Quality Of Data ◽  
Diving Depth ◽  
Sea Bed ◽  
Wide Range ◽  
Logistic Support

As opposed to ROVs (Remotely Operated Vehicles), self-propelled, unmanned autonomous underwater vehicles (AUVs) are becoming increasingly important since, unlike ROVs they can operate completely self-sufficiently, i.e. independent of the carrier platform and cable at practically any depth and for long periods of time, require only minor technical and logistic support and can be used in regions which are inaccessible to manned submersibles or ROVs (e.g. under ice regions). In other words, AUVs are distinguished by a wide range of applications, the extremely high quality of data collected, their very cost-effective operation and the large standoff capability to the carrier platform, the latter bringing about a distinct improvement in terms of carrier platform safety e.g. for military missions. Due to these advantages over conventional systems, AUVs can be employed for a whole variety of applications, such as the following in the commercial sector: • Sea Bed Mapping, • Pipeline and Route Survey, • Inspection/Control, • Site Clearance, • Debris Survey, • Science – Search – Environment – Geology, • Harbour and ship’s hull inspection. Moreover AUVs will play an important role in the military scenario like mine countermeasure as well. Obviously, one single type of AUV will be unable to cover this entire spectrum if — above and beyond the aforementioned applications — one considers the different operating depths ranging from coastal regions (about 10 m) to deep water (approx. 4000 m) and the various possible carrier platforms (helicopters, ships, submarines, shore stations). On the other hand, the development and use of one specific type of AUV for one or a very limited number of mission types would be very expensive, both in terms of costs involved and necessary logistics, and would hardly be acceptable on the market. The solution to this problem is the “modularity” of the AUV subsystems as well as a family concept for the vehicle design. To implement this strategy, ATLAS ELEKTRONIK has forced the development and marketing of an AUV family for a wide array of missions. The family starts with the SeaFox-IQ, a very small and lightweight (40 kg) AUV for 300 m diving depth, based on the extreme successful mine disposal ROV SeaFox. The big brother is the SeaStout, a 100 kg AUV, designed for 300 m too. The SeaOtter Mk1 and SeaOtter Mk2 AUVs are 1500 kg and 1100 kg vehicles for 600 m operations. The leading edge is the AUV DeepC, a 2500 kg experimental vehicle developed for 4000 m depth and up to 60 h endurance. The ATLAS AUV family offer a lot of hard- and software commonality to ensure that serviceability is maintained, while having a high degree of “customisation” in key areas like payload sensor selection ensuring they will meet customer needs.

Sports Diving Depth Gauges: Test for Accuracy

1983 ◽  
Vol 54 (7) ◽  
pp. 72-73
Author(s):  
Robert F. Leahy ◽  
Peter R. Lynch
Keyword(s):  
Diving Depth
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