Rip currents are strong and narrow currents in the surf zone that extend seaward of the breaking waves and return water seaward that has been transported into the surf zone by breaking waves. Rip currents are found on high-wave beaches with bars with the rips cutting through the bars in the form of distinct channels. Rip currents can be very strong with flow velocities of 1-2 m/s and are the main hazard to surf zone water users. According to lifeguard records, over 68% of incidents ('rescues') on UK beaches can be attributed to rip currents. A similar percentage is reported from Australia and the USA and, in Florida alone, over 100 people drown each year due to rip currents. Rip currents not only transport people out to sea, but also other material, such as sediment, plankton, nutrients and pollutants. Rip currents are therefore also important for beach erosion and surf zone water quality. The importance of rip currents for beach safety is well recognised by coastal scientists and lifeguards, but we do not fully understand what controls their flow strength and pattern. Our understanding is particularly poor for rip currents on beaches with a large tide range. On some beaches, strong rips cut through bars and sweep swimmers out to sea, whereas on other beaches the rip current develops a large circulating eddy within the surf zone. The risks posed to surf zone water users, and the potential for beach erosion and surf zone flushing, will depend strongly on the type of rip circulation. We believe that rip currents are strongest when all wave breaking occurs on the bar and none of the waves break in the rip channel. We hypothesise that under such conditions the rip generation mechanism is maximised and this depends on wave conditions, tide and bar morphology. All three factors vary over time and even subtle changes in any of them may have significant repercussions for the rip circulation. The overall aim of this project, Dynamics of Rip currents and Implications for Beach Safety (DRIBS), is to test this idea by measuring rip currents under a variety of wave, tide and beach conditions, and complementing the data analysis with computer modelling. We will conduct a 6-week field campaign on two high-wave, large-tidal beaches along the north Cornish coast where mass rescue events of upwards of 150 people per beach have required simultaneous rescue due to rip currents. During each of these campaigns, we will install several instruments in the surf zone that will measure waves, tides and rip currents at fixed locations. In addition, we will use a large number of specialist drifters that measure the complete rip current pattern. The drifters will be released in the surf zone and will move according to the nearshore current pattern. Their location will be continuously monitored (using GPS) and the data from the drifters will provide useful information not only on the strength of the rip current, but also on the type of flow pattern. The drifters are designed to behave like human beings and their movement therefore mimics that of passive bathers. The information collected during the field campaigns will be used to develop a computer model that is able to predict the rip flow pattern for any given wave, tide and beach condition. We will then use this model to develop tools that can be used by lifeguards to determine the rip current risk and develop strategies to deal with this risk. This research project involves the Royal National Lifeboat Institution (RNLI) as a Partner and the RNLI will be involved during all stages of the work. The partnership will be mutually beneficial: the RNLI will help us with the field measurements by making available their dedicated staff and facilities, and we will pass on the research findings to the RNLI via workshops, lectures, leaflets and other types of publications. More importantly, the research findings will be incorporated into the RNLI's risk assessment procedures and resource management tools.

A recent NERC-funded proof of concept award successfully demonstrated that Global Navigation Satellite System (GNSS) signals reflected off the sea surface and received by very low cost (<£30) GPS receivers can be used to estimate the difference in height between the receiver and the water. This represents a method of remotely sensing tidal elevations and, if averaged over time, mean sea level. These could be routinely and remotely measuring sea level at a cost that would allow unprecedented numbers of systems to be deployed around the world by organisations of all sizes and levels of funding. Here we propose to take the initial proof of concept from TRL 3 up to TRL 7 by designing a self-contained unit that receives, records and processes the required signals to output a tidal water level in near real time and at a target hardware and assembly cost of less than £100. The demonstration units will be tested and used by our project partners, the RNLI, initially to provide tidal information at an intertidal causeway with a history of RNLI rescues of members of the public who have become stranded by the rising tide. The technology has the potential to be rolled out not only across the UK but globally, potentially as open source designs & firmware, revolutionising the ability to collect tidal and sea level data at an unprecedented price point and operational simplicity.

It is widely accepted that "suicide prevention is everybody's business," but most research has focused on the role of health professionals in identifying and managing suicide risk within clinical settings. Much less attention has been paid to the contribution that members of the public (with no healthcare training) can make, or the resources they need in order to do so. In a previous project funded by the MRC, we examined the role of family members and friends. We used qualitative methods to shed light on the difficulties they face in trying to interpret signs of a suicidal crisis and decide what action, if any, to take. We then formed a partnership with all the leading suicide prevention charities to develop and evaluate simple public education materials that address those difficulties. Those resources are designed for people who are concerned that someone close to them may be suicidal. We now wish to use the same approach to address a very different scenario, namely the 'Stranger on the Bridge'. This was the title of a highly-acclaimed Channel 4 documentary, broadcast in 2015, which told the story of Jonny Benjamin, who went to Waterloo bridge to take his own life and was prevented from jumping by the kindness of a passer-by. Of the 6,000 suicides that occur in the UK each year, around a third take place in a public location. Many of these involve jumping from bridges, cliffs and high buildings, or use of the railway network. Some of these deaths may be prevented by the installation of physical barriers, but human intervention will always play a vital role. This is most likely to come from a passing stranger, but few people know how to recognise someone at risk or are willing to get involved. We want to increase the number of people who are able to recognise and reach out to someone in a public place who may be contemplating suicide. First we need to gain an in-depth understanding of the Stranger on the Bridge scenario from the point of view of those who have been involved, both as 'rescuers' and 'rescued'. We will advertise for both through adverts in mainstream and social media, aiming to interview around 10 people with experience of being rescued and 20 people with experience of intervening, including some railway staff. We aim to discover: a) what signs and signals a person contemplating a suicidal act is likely to exhibit; b) how passers-by interpret those signals and understand what is happening; c) what fears people have about intervening and how they decide whether or not to do so; d) what are the core components (both verbal and non-verbal) of an effective intervention by a lay person. We will also interview some people who have no experience of this situation to find out about wider public attitudes and fears. Using the findings, we will work collaboratively with a range of non-academic partners to formulate key messages and develop a set of resources to be used in an educational campaign. We will start by developing a simple leaflet for distribution to members of the public, and an online version of the same. We will also develop a 90-minute face-to-face training session for staff at the sort of locations that are used for suicide, e.g. bridges, multi-storey car parks, rooftop restaurants, cliffs and coastal paths, and railways. We will evaluate these in a later study, and hope to go on to develop other materials using different media at a later date. Our strong project group includes academics from the University of Exeter, the documentary-maker Jonny Benjamin, who survived his own suicidal episode thanks to a stranger, together with representatives of the suicide prevention charities, Public Health England, Network Rail and the RNLI.