Simrad ITI

Navigation for fishermen has always been based on the position of the vessel - because this was what we could locate.  Boats were the platform on which we used sextants, and then radio bearings, Loran and Sat Nav, now they serve as platforms for GPS and DGPS antennae.  We have positioned ourselves based on the vessel for two reasons - because that was what we could locate with the technology in existence, and we didn't want the vessel to run into rocks and other vessels   But, and think about this - Is this really important for fishing?

With due apologies to the brethren - and yes, we have also taken sextants out on deck an hour before sunrise - once a trawler gets clear of the shoals, the position of the vessel isn't important at all.  What is important is where is the trawl?  And equally important how does the seabottom appear from the perspective of the trawl.   Knowing the answers to that question is what enables you to pilot the trawl into the rich micro fishing locations, and jockey just clear of the obstacles on the bottom.

The Simrad ITI system locates a trawl net, as to depth, distance and bearing from the vessel.  There are several more such systems in the pipeline and we strongly feel that this represents the future of trawling.  When the technology becomes available such position locating will also represent the future of long lining and jigging as well. 

Marimsys BRIDGE shows the vessel position normally on whatever chart is selected in the plotter.  If the vessel is fitted with Simrad ITI, the position of the net also shows in the plot window.  The net shows as it moves in and around the bottom obstacles as shown with the micro detail of a Marimsys chart. 

Here is an illustration 

In the screen shot all of the net reference windows are shown, you can get just about the same view from the Simrad ITI itself and don't need those windows.  What you need is the view of the net, scaled exactly to size moving around on the bottom.   You would normally use Marimsys BRIDGE with none or perhaps one of the small windows open.  You see the bottom and where you want to go, and where you want to stay away from.  You guide the net - a bit to port, a bit to starboard to take it down the trawl track that you determine is the best.  You can literally scrape up against the sides of ledges with the trawl doors - and it is in those difficult places that many species of fish congregate.  With the Marimsys Chart you can see the obstacles on the bottom, the "stubbies" that will hang up the trawl, and simply steer right around them.  And for the trawl routes - you see them, and keep the net going right down the track.

With Simrad ITI and Marimsys BRIDGE you can go off into the most difficult areas that you know of - and trawl them.  We received a chart last year, accompanied by a Marimsys BRIDGE soundings data file from a client in New Zealand.  The chart was a hand workup of a volcanic caldera, that's the hole inside a volcano, enclosed by a more or less round rim where the top of the volcano has blown up and off.  The chart sent us was entitled "Valley of Death", we were told that no-one had ever trawled that valley successfully, they all hung up.  Apparently quite a few of Kiwis had tried - and those chaps are the ones who invented pinnacle fishing - they wrote the book on fishing seamounts.  We sent back our Marimsys Chart, and instead of our normal Latitude and Longitude title for the chart, just for the hell of it, we decided to call the chart, "Happy Hunting Ground".  Our client saw routes on the chart that would never have been visible without the Marimsys Chart and went in.  First try with his trusty Simrad ITI, he dropped the net right where he wanted to, doglegged about on the run, and hauled up 16 ton of orange roughy - yep, paid for those Simrad ITI and Marimsys BRIDGE systems, right quick.