It is August, hot and mostly calm. Not the best conditions for fishing, as it can get too hot for many fish and the temperatures certainly put anglers off a long day in the sun.

Chumming is still effective, although a lack of breeze and a merciless sun can make it uncomfortable for most people. Many of the preferred fish, the school-sized yellowfins, actively avoid the heat of the day by staying deeper. This makes early and late in the day the best time to put in the effort for this species. Small game and blackfin tuna, which abound in warm water, should please consistently.

Trolling can be a bit hit-or-miss. While it is still too early for the autumnal wahoo run to offer any excitement, there are enough single fish around to make it possible to snag a few. Barracuda are coming into their own and will happily devour carefully rigged baits intended for wahoo. While this does not sound like much, it can get to be frustrating really quickly.

Up until recently, Captain Alan Card’s Challenger has enjoyed a good run of catching large yellowfin tuna on the troll. These fish were large: 120 pounds or more and capable of giving even a fit angler a good workout. That activity seems to have eased up, but there could well be another influx of large tuna at any time — and that could make for some good sport. Similarly, large tiger sharks are often commonplace on the Banks and, once hooked, can provide a good tug-of-war before being released as per the law.

Tomorrow, the Marlin Release Challenge takes place. An all-release tournament, this is primarily for local boats. Unlike the big-money tournaments of last month, this event is a much less money event, does not have the strict rules that apply to most big-game tournaments and prohibits the use of sonar. In particular, side-scan sonar.

And therein lies a much debated point of contention. Just how much of an advantage does it give a boat equipped with it over ones that do not.

The actual device is simple enough. Similar to traditional sonar, which has been used to determine depth for more than seven decades, this utilises the same technology to probe the water surrounding rather than directly under the boat. Very high-quality depth sounders not only picked out details of the bottom but would occasionally pick out other objects that were above the bottom yet still below the vessel. Think of the old war movies in which a destroyer hunted down a submarine using sound pulses; this was one of the prime uses for sonar, which at that point was in the early stages of development. Postwar, the technology was further developed, costs reduced and eventually marketed in many places as “fish finders”. Further refine the electronics and precision and, inevitably, quality and accuracy improved beyond the original inventor’s wildest dreams.

As a result, modern upmarket depth sounders were highly sophisticated, able to pick out the finest details on the bottom. This led to refined uses such as detailed mapping of the sea floor, finding wrecks or other materials and a lot of the stuff that has been the premise in bestsellers and detective shows in the movies and on television. Take that and apply it to the horizontal rather than the vertical, and that is the application of side-scan sonar.

How accurate it is? Well, the gear that goes for more than most local boats cost will pick out any individual fish that may be lurking in the vicinity of the boat.

While it won’t make the fish bite, there has to be some advantage in fishing in an area where it is known that there are one or even several large fish cruising below the surface. Contrast this with good old-fashioned trolling where the anglers blindly drag their baits over the ocean hoping to encounter a fish in the mood to bite. In many instances, there may well be no fish for miles; just the anglers’ expectations or hopes that they will get lucky.

It is nice to know that your fishing effort is being put in where there are some fish for sure. Not surprisingly, this creates rancour when it comes to competitions where boats so equipped are thought to hold a huge advantage over those that lack the equipment. This is generally not a problem for the big-game fishing boats that regularly ply the tournament circuit. Their answer is simple: just install the side-scanning sonar. Not so much a solution for the local boat that marlin-fishes three days a year, but can make a huge difference to results.

Despite fine weather, travels and school holiday activities help ensure that there will not be a whole lot of adult action for the next few weeks. The very popular annual junior tournament in memory of Niel Jones is slated for next Sunday. It is open to under-17s, with details available on social media at a number of sites. This is always a fun event, with lots of prizes and an incredible variety of Tight lines!!!