Maybe you could make a submission to organisations like the coast guard, beach life savers, sail training, school swimming education, even the military / navy, and they may be interested in assisting, advising, giving pointers, or other places to ask for help. Show a succession of changed ideas, and next generation prototypes, or even mock ups, to make your concepts obvious, so that someone else's imagination can run with it, and give you feedback. Remember, the squeaky wheel gets the oil, so squeak up. I imagine a soft boogie board with rope loops on edges, electric powered small jet unit, flashing lights and epirb, remote control guided to a troubled swimmer; having no knowledge of your concept, or usage scenario.
I'm building a hat, - a special hat, but not high tech. How difficult and expensive can that be ? I've seen similar but inferior ones selling for over $200 US, and even the rubbish ones are quite expensive. I sketched ideas, and wrote lists of needs, and wants, and future possibilities on paper over months of deep thought. I looked for ways to make the basic shape of prototype 1 in a quick and easy way, and found a suitable shape which needed modification straight away. I made some basic extra form work and then produced the first fibre glass shape, then added to it. Needed some more parts and found a suitable donor item, modified and fitted it. First testing showed improvements needed. By then I had spent about 50 hours or more - unpaid, and used maybe $50 of materials. This is just a hat. To pay a professional to get this far would be maybe $3000 - $4000.
So then made improvements, and also added to the basic shape, and fitted a major accessory, another 10 hours work and $50 in off the shelf materials. Testing sequence No 2, and it needs more additions, so another 2 hours, and parts free (it pays to recycle). Testing sequence 3, fairly comprehensive testing in most conditions over many months, so another 20 hours working on it, taking notes, and another free part from my hoard. Professionally done maybe $6000 - $10,000 so far; I don't pay myself, so I'm cheap labour. It is a proven concept now, and ready to make a commercially acceptable version, requiring making a mold ready to produce prototype 2; started making mold 2 costing another $200 materials and 10 hours labour, for a very rough lump requiring cleaning, adding, shaping, polishing, and that's an easy part, with another required part being much more complicated. To then make Not a finished product, but a complete prototype for further testing, and manufacture / tooling design, and display to potential manufacturers, who may hate it, or steal it. Or I may do limited production runs myself from my own molds, which will take time and be more expensive per item. Not a huge market yet, but can be adapted to many uses, situations, and industries, if I can mass produce it before someone else does. Do all you can yourself, or with a small local team of trusted people if possible.
A note about getting others to do specialist work. A country has cheap labour, and tool rooms, and they can make your mold cheaper than anywhere else. Plastic injection, or metal pressings, or anything really. They make 2 or 3 molds / dies to your specification, test them, and sell you the worst acceptable one, but keep the best ones which they put into full production, to sell the produced items in countries away from you. When your local market is saturated, and you look for sales afar, the need has been largely satisfied already. Beware of industrial espionage.
I lost a good job due to the company's products being copied, exactly, even features from long obsolete fittings, and styles of internal machining marks. The R & D people could barely tell original and copy apart, besides different textures and colours of plastic.