To cut back seriously on paper charts, the greater vulnerability of equipment on a small craft to accidental damage would have to be taken into account, including lightning strikes. For small boats it is already possible to buy, at a price, extremely robust electronic systems, including waterproof laptops that withstand impacts (costing several thousand pounds), and high capacity lithium battery back-up packs; small back-up generators have also become cheaper in recent years and can be accommodated on many mid-sized cruising yachts.
At a cost, robust weather and shockproof electronic navigation with reliable backup systems should therefore be quite close to achievable now on a yacht. Even if we fall well short of the rigorous standards of an ECDIS system, we will not be carrying 100,000 tonnes of crude oil or thousands of containers, so perhaps we can be allowed to be rather less tough on the backup specifications. Similarly with training: new courses may be necessary, but perhaps not the 40 hours plus specified for ECDIS for commercial ship deck officers.
Here is our current navigation equipment list plus a few items we plan to get. We rely on maximising the number of independent systems, including some which can be isolated from the boat’s electrical and aerial systems ie reversing the current fashion for electronics integration. Whether isolated equipment can be protected enough to see us through a lightning strike is a question that we are still thinking about.
We also try where we can to use portable equipment that we have bought for other purposes, keeping down the boat budget, but we draw back from the high costs of top-end equipment such as water and shockproof computers and screens. Others may have very different and perhaps much better ideas – it would be good to hear them, and especially any thoughts on protection against lightning (we had a strike 12 years ago that burnt out some instruments but not all).
This list is for cruising British and nearby waters.
- Basic cockpit chart plotter using vector charts.
- A separate large screen chartplotter at the chart table is a good option. But we have stuck with a standard laptop in an easily removable protective mount. The laptop is plugged into the boat’s 12 V system; two advantages over the plotter are that it is programmable and could be very easily switched to a backup external battery specifically designed for it (see below).
- iPhone or similar with Navionics or C-Map charts in a waterproof case, kept fully charged.
- An old fashioned stand-alone GPS at the chart table, feeding the DSC radio.
- An AIT system, with its own GPS, displaying ship positions on the cockpit chartplotter, where it is of most use, but with a USB connection to the laptop in case backup is needed.
Plus in due course:
- An iPad or Samsung Galaxy 10 inch screen tablet, with full vector charts and navigation software, with a bracket to hold it at the chart table and a 12V charging lead. With a waterproof case, the tablet could also be used in the cockpit in reasonable weather for a few hours at a time, held in a bracket.
- Two or more 8 amp hour lithium external batteries, kept full charged, capable of recharging the laptop, the phone and the Samsung if the boat’s electrics fail.
- If laptops with separate screens improve, a screen mounted (removably) on a bulkhead at the chart table and a keyboard on the chart table connected by bluetooth would be an ideal replacement for the current standard laptop. It would have the programmability and screen size of PCs and the convenience of tablets, while protecting the screen better than a normal laptop.
- For those with a big enough boat (not us): a generator and electrical control equipment to feed a spare battery to provide a complete standby power system for emergency lights, radio and navigation equipment.
With this level of backup, is a yacht safe if it leaves most of its paper charts behind (perhaps keeping just a few small scale charts covering a wide area)? Does it matter that it would be ignoring the legal warnings by using leisure charts in practice as the primary means of navigation?
This partly depends on how seriously we take the inadequacies, as C-Map and others describe their own products, of leisure charts, which is a whole new issue for another article.
Post published 6 April 2013
Next, an example of paper and electronic chart inaccuracy: Orkney roulette