Not so long ago the only way to investigate any problem below the waterline – whether suspected plastic sheeting around the propeller, rudder problems or impact damage – was to go into the water wearing a dive mask. At sea, even in relatively calm conditions this is fraught with danger thanks to the risk of the aft sections of the hull crashing down onto the swimmer’s head in any kind of waves or swell.
Today’s action cameras make underwater inspections significantly easier –you can strap a GoPro to a broom handle or boat hook, point it in the right general direction and then review the footage afterwards. However, this is still not a total solution as the wifi won’t work when the device is underwater and what you really want is to be able to see the footage in real time on a laptop or tablet screen.
There’s a growing number of small submersible drones, products like the Gladius submersible that will do exactly this for a cost of less than €1,500. While this makes it relatively expensive at the moment, as with airborne drones submersibles are likely significantly drop in price over the next couple of years.
Another option is that, although only the largest yachts typically have space for full size diving equipment, a number of manufacturers produce mini dive kits with smaller bottles that will give up to around 20 minutes of time under the water. Providing the boat is in a safe anchorage – the risk of a head injury from the hull moving up and down is too high otherwise – these can be invaluable for checking potential problems underwater, clearing a fouled propeller, or for a final clean of growth off the hull.
Even this area looks set to benefit from emerging submersible technology. Already devices such as the KeelCrab will perform an analogous role to a robotic vacuum cleaner or lawn mower in automatically scrubbing the bottom of a boat while it’s afloat. Given a lift for a scrub can easily cost £400, even for a modest size yacht, it’s clear these have the potential to repay their initial cost several times over.