BOATS, KAYAKS & YACHTS:
WHALES & DOLPHINS
Crew and guests are always impressed when they can hear as well as see whales and dolphins. However, in most cases, we can hear them long before they are sighted. There are, of course, many other sounds generated by all kinds of sea creatures and amphibious animals. Go to our ‘Listen’ pages to hear a few of them.
DRAGGING ANCHOR ALERT
Many inexperienced boat owners toss out the anchor and hope it holds. Those with more experience realise that anchors have a nasty habit of dragging when you least expect it. Will it hold if the wind picks up overnight? And, even if you are 100 percent confident that your anchor is set well, what about the other boats in the anchorage? One dragging anchor can dislodge many others as it drags across the seabed.
If you already have a DolphinEar on board for listening to cetaceans you can use it to monitor your anchor set. If it should start to drag you can be alerted early as the sound of scraping along coral, or rocks, or the sounds of the anchor against moving sand. You will hear the same for neighbouring boats as well – giving you plenty of time to warn them and avoid disaster.
NIGHT INTRUDER ALERT
If you are a boater, particularly if you are a cruising yachtie, you often find an idyllic anchorage that looks perfect during the day – not another boat in sight. As night falls however you begin to realise that you are very isolated. You thought you saw a light briefly shine from shore. What, or who, is that? Are you safe here all night? Will another boat try to join you sometime during the dark night? Will someone quietly launch a small boat from the beach and board your boat while you sleep?
These are normal occurrences for those of us who go out in boats. In those circumstances we put our DolphinEar on watch by connecting it to a speaker system. Then we can enjoy the gentle sounds of the sea around us and be assured that if anyone approaches we will hear them long before they arrive. Their boat sounds will awaken us from a sound sleep.
Detecting approaching boats is also a useful tool in marina security applications. DolphinEar has been used for years in large and small marinas as well as for small harbour security. CCTV cameras give the impression of security but are there to help with after-
A spate of boats thefts in marinas was stopped when the thieves were caught in the act. What tipped off the security guards? A DolphinEar placed at the marina entrance clearly picked up the sound of a small boat engine entering in the wee hours of the night. It was wired directly to the security desk and within minutes the culprits were apprehended.
Several DolphinEar users have reported they used their hydrophones to find the source of small leaks in their boats’ wooden hull. Of course, DolphinEar is used in industry to help locate leaks but we never thought of using it on leaky hulls!
One thing we have observed (and recorded) in the past is the use of a DolphinEar to check out the engine and prop system on a passing boat. Even at distances of several hundred metres, defects in the prop shaft, thru hull prop gland, and propeller can be detected, A missing or rough running engine is easy to hear as well
Have a listen to our recording of a boat leaving a marina in the LISTEN section.