Advanced Towing System

When the 66m catamaran Hodor was launched in 2019, it amazed even the most seasoned insiders. Although a large boat in its own right, Hodor had been built as a shadow vessel for a superyacht, a floating toy box designed to carry all the gear and playthings guests might wish for, from jet skis, all-terrain vehicles and trail motorbikes to an Airbus H145 helicopter.

Hodor represents perhaps the most extreme end of superyacht support vessels, but it also illustrates a growing trend: tenders and shadow vessels of all kinds are becoming larger and faster.

Many owners have support vessels or chase boats that cannot fit into a superyacht tender garage. These tenders are bigger, but also heavier and more complicated to tow. Yet they are also the main form of transport for guests, so crews need to be able to take them between cruising areas.
Inevitably, damage to tenders or loss has become more expensive. The risks led to insurance conditions that could restrict passage planning, such as maximum wind strength or exclusions for towing at night. Crews might have to wait for weather to pass that they would previously have been able to go in.
So owners, captains and insurers have been looking for solutions to reduce deductibles and extend the conditions in which tenders can safely be towed.

says Michelle Van Der Merwe, superyacht account manager at Pantaenius.
UK electronics company TSM Systems were looking at the mounting issues too. “Towing can be a problem; the line can part, it can be damaged and a boat can sink,” says William Ferlazzo, the company’s head of sales.

“Tenders were no longer 5-7m boats; they were often 12-15m boats which cost $1 million plus and were built very specifically for the yacht. And if you are chartering a 50m yacht for $450,000 a week and the tender is damaged or lost, it can really mess up the guest experience. It’s often not easy to find a substitute of a similar quality.”
TSM realised that the technology existed to alleviate some of these difficulties and in 2021 designed and launched a remote monitoring system, TowPro. In-house technical input came from Vincent Geake, a well-known professional yacht navigator and former performance information systems for the Team New Zealand America’s Cup team, and David Robins, a project delivery specialist with a broad background in marine, electrical engineering and marine telematics.

SO HOW DOES TOWPRO WORK?

Although AIS data can be used on tenders and chase boats when they are in use independently, regulations do not allow it to be used on a vessel under tow. TSM Systems therefore had to develop a different solution. A specially developed VHF marine data exchange system (VDES) module was created. “We use two VHF antennas, one on the yacht and another on the tender [and broadcast] on a frequency that sits between AIS bands so only the yacht can see it,” explains Ferlazzo.
The TowPro system sends a continual stream of real-time data to the yacht. This is displayed on a touchscreen in the bridge which can also be interfaced to ECDIS through a multiplexer or alarm system on the bridge. It shows information such as tow length, bilge water level and pump activity and battery state, as well as pitch, list, roll and yaw, information that illustrates the state and load of the tow. These alert crew to issues on board the tender day or night, including problems that cannot readily be seen even if someone were keeping watching from the stern of the mother ship. If any of the pre-set parameters are exceeded, the TowPro monitor triggers audible and visual alerts.

The system can also set a geofence 150m from the mother vessel. If the tow line breaks, TowPro will activate the tender’s emergency AIS unit to show its position and flag the boat as a vessel not under command. An optional three-year package is available for a web-based global satellite tracking service using the Iridium network, which allows the tender to be located anywhere, then tracked so it can be recovered. It uses an integrated battery that gives around seven days’ continuous operation.
The benefits of TowPro have quickly been seen by yacht management companies and insurers. “We have found after presenting to the market at the METS Trade Show last year that they are pushing to have a system on board that helps the captain and the management company to understand what is going on,” says William Ferlazzo.
“Insurers have been able to reword some of their stipulations. Before that, yachts were often not allowed to tow at night, in [winds of] more than Force 3 or more than 60 miles from nearest port. Now they can be covered for towing at night or further from coast and up to Force 4,” he adds.

confirms Pantaenius’s Michelle Van Der Merwe. “The introduction of this new clause has only been available in last few months so we don’t yet have data on claims improvement, but from an insurance perspective, any system that helps keep loss or damage to a minimum is obviously very interesting. Equally importantly, Pantaenius is keen to support innovation.”

TSM Systems are already hard at work on the next generation system. ‘TowPro 2.0’ will add other monitoring data and alarms such as fire, anti-theft and anti-intrusion alerts. The company is also creating a mobile app for the system, so that information and location can be viewed remotely from anywhere.
Towing a tender can be fraught with concerns for captains and watchkeepers. If they are alerted to any problems as they develop, they have more options. They can, for example, transfer someone aboard while it is still safe to do so, or seek shelter to stop and check the situation out. An early warning can help avert damage, or even the loss of an essential asset.