Google maps is better
Very difficult to use but have heard good things from other Captians
I sail Alamitos Bay in Long Beach, CA. Although I have Anchorages layer OFF, the chart still indicates all anchorages. So many are shown that they overlap and are unreadable. On my iPhone 6 Plus, the chart is useless. Tech support claims that the anchorages are the names of the 'water areas' and will show even with the Anchorages layer turned OFF. $30 bucks out the window, as far as I'm concerned.
Crash & calibrate,seems that's all I do with this app. This app is not even good for recreational boating. Don't waste your time & money.
Crashed so often that I couldn't even view harbors. Vey allow on my LTE iPad Mini. Depth contours 0-18', 18-30', and 30-600'are less than ideal. I would want to navigate my boat using this app and its maps.
I give it 5 stars because it is an intuitive app, and if you do any type of weekend trip on a cabin cruiser near the major bays, it's probably fine. I like the fact that it pings GPS every minute when in background mode to save energy. I like the intuitive interface, and myriad options one can set. Their tech support is great. I've been emailing them and they have done all they can to work with me, and even suggesting a refund. I appreciate a company like this but I did ask them to update their description to make sure people know about the Tennessee River depth contour issue. I bought a competing app after I bought SeaNav and I initially considered refunding the SeaNav but I like it enough reasons to keep them both. I'm not a pro but I have spent a lot of my life in twin engine Chris Craft cruisers as well as little runabouts. I keep laminated official marine charts and realize these apps are no substitute for charts. I CANNOT RECOMMEND THIS APP FOR THE TENNESSEE RIVER, particularly for its lack of detail upriver from Pickwick Dam (Pickwick Lake towards Wilson Dam) and lack of more detailed depth contours. There are underwater stumps galore and you must stay in the channel you need to follow. SeaNav does not show a route and does not label any of the obstructions - even though it would probably be impossible to pinpoint them all. I bought this app for the depth contours that showed up in the preview images, thinking they would be on all US waterways. Seems their map source does not offer those, so I get only two depth contours on the Tennessee River through North Alabama: >9ft and <9ft. Seriously. Inaccurate rendering of depth contours even in slews that are 20+ feet deep it is a blue color representing <9 ft deep. We do a lot of activities in our runabout in shallow slews and also a couple miles up from the mouth of the Elk River. The mouth of the Elk River has channel markers but this app does not show a route through that channel. The river renderings stop after you leave the main Tennessee River. Elk River on Wheeler Lake? forget it. Shoals Creek on Wilson Lake? forget it. Bear Creek on Pickwick Lake? forget it.
The app is crisp and responsive on my 4th gen iPad -- and the AR feature was a huge help in confirming landmarks while sailing through the fog along the Monterey coast.
They keep working on this app and its become much better, performance is good on my iphone 5
The charts draw soooooo slowly, this app is virtually unusable.
It crashes about half the time thus far