AVES MARINE Ltd                        Authorised and approved by Onwa Marine Ltd                                UK and EU sales and support 


Onwa K-Charts.


K-Charts is Onwa's own charting system and supplied by Onwa free of charge. Being free to Onwa owners doesn't mean its a lightweight product - K-Chart software is a completely usable navigation tool that compares favourably to other chart cartography that will set you back quite a lot in terms of cost.  

With every new plotter that we sell we bundle a K-Chart of the customer's choice, this might be whole of U.K (which also extends to the North Coast of France and Holland) or one of four areas that cover the rest of western Europe. Additional charts, e.g if you wanted the whole of Europe, would be free as a download or just the cost of the SD cards required plus postage if you wanted AVES Marine to supply the charts ready formatted onto SD cards that you just have to plug into your Onwa plotter to use.  

K-Charts are supplied free of cost as a sales incentive without warranty as to their accuracy. The warning regarding accuracy is somewhat misleading as it is almost always the case that electronic software for charts and maps comes with such a warning advising that it is the responsibility of the user use the software with a caution - likely even your car Sat-Nav' will have this.  

Our caution and condition for you, the user, using K-Chart is as follows:   

K-Charts, as with all electronic navigation software, should not be relied upon for safe navigation at sea. They should always be used in conjunction with up to date paper charts and it is the responsibility of the navigator to ensure that this is the case. K-Charts are supplied strictly on this basis and no warranty is given as to their accuracy. Acceptance of this by the navigator is conditional upon using K-Charts. 

However, having given the required caution, from my own experience using the UK K-chart in my home sailing area around the Kent coast, I can say that they compare very favorably with other navigation software. Depths, hazards, navigation aids etc are very similar to other systems.  

K-charts only work with Onwa plotters so they won't work on your Raymarine etc! 

Some sample images from the U.K free cartography bundled with every new plotter. Click on any image to go to full screen - be sure to close the full screen by clicking on the black X at the top right hand corner of the actual image...not on the red X  at the top right of the screen as this will close your browser down.

Solent 0.7 nm Zoom


Dunkerque 1 nm Zoom


Goodwin Sands off Pegwell Bay and the estuary of the River Stour between Ramsgate and Sandwich in Kent. .2 nm Zoom


Entrance to Princes Channel in Thames Estuary. 1.5 nm Zoom. Plotter curser (red cross) at entrance to Princes Channel.

Compare Admiralty chart 5606 image of the same area to the K-chart above. Note that Admiralty chart is 10th edition 2012 whereas K-chart is 2014 so there may be slight differences.


Shipping channel River Medway approach, 0.5 nm Zoom. Shipping channel clearly shown. Note hazardous wreck just to the north of the shipping channel marked by four perimeter buoys.

Thames Estuary/River Medway entrance: same area as the previous image but at 2 nm zoom.

Thames Estuary @ 5 nm Zoom - sandbanks and wrecks all around - a good reason to have a plotter installed perhaps?


Margate Sands @1.5 nm Zoom


Thames Estuary - note the four warning perimeter buoys marking the wreck of SS Richard Montgomery and how close this is to the shipping channel just to the south of the wreck.

Richard Montgomery masts still showing

The SS Richard Montgomery is a WW2 wreck that sank in the Thames Estuary in 1944 loaded with munitions. It is generally considered too dangerous and too expensive to remove the estimated 1,400 tonnes of explosives which remain viable today (it is rumoured that the figure may be as high as 3600 tons!). It is speculated that if the munitions exploded it could create a mini tsunami and cause widespread damage to the surrounding area. It is a ticking time-bomb that could, possibly, explode at any time. The wreck lies in two parts in a North-South position marked by an exclusion zone of four warning buoys. Wreck position is 51.27.996N 0.47.090E

A really fascinating You Tube video of The SS Richard Montgomery taken from the BBC series Coast. The quality could be better but the content and the story it tells is a must watch. Click the You Tube icon to watch.

An interesting and informative site - worth taking a look, click on the blue link address.


2017 UK Government report on the wreck. Click on the blue link address to view; this is a long report but the contents are fascinating.          Well worth a read when time allows.

2017 UK government survey on SS Richard Montgomery

            SS Richard Montgomery on WIKI.