Aquanaut has been building steel boats from 7 to 20 metres in length in Holland since the 1960s and is still family-owned today. The Dutch shipyard has a diverse range of products. It currently has more than six boat series, with a total of over 30 models on the market.
We are sailing a boat from the Andante series, which is available either with (AC) or without (OC) aft cabin and as OC also with flybridge. The word Andante, known from music, is both the name and the programme and means something like striding, i.e. a rather leisurely, calm pace. We tested the 438 AC. The boat is equipped with an engine and shaft system, but there would also be room for a second one in the engine compartment. The boatyard primarily uses Perkins, but also offers other makes.
This is suitable for steel displacers, which only travel "sensibly" up to the theoretical hull speed anyway. Above that, the increase in speed and consumption are in an unhealthy ratio.
It is best to drive a displacer in the range where the highest engine torque and lowest specific fuel consumption correspond closely with each other and both are still below the fuselage speed.
For our test boat this means that the Perkins M150Ti (is an M225Ti throttled for NL) has its highest torque at 1400 rpm, and the theoretical hull speed of the Andante is around 8 knots.
After analysing our measurements and using the engine manufacturer's consumption values, we see that at 1400 rpm or a speed of 6 knots, one tank of fuel is enough for a theoretical range of just over 1000 nm, plus 15% reserve. At this speed, the boat makes almost no waves and the lapping of the water is louder than the engine noise, which we measured on the aft deck at 69 dB/A at the helm.
At top speed (9 knots), the sound pressure (75 dB/A) increases to entertainment volume, and the ranges shrink below 300 nm plus reserve. In other words, from cruising at 1400 to full throttle at 2500 rpm, we have increased the engine speed by 44%, while the range has shrunk to around 1⁄3. In other words, travelling 3 knots faster increased fuel consumption by more than five times. You need to be aware of this if you are travelling in areas where you are going against the current, such as on the Rhine.
Good work, smooth running - what more could you want?
Only one drive means one good and one less good side when manoeuvring at slow speed, which is why the bow thruster is standard and a stern thruster is recommended. Apart from that, our test boat hangs perfectly on the rudder and holds its course well in a straight line. The shipyard manager was also surprised by the oversized curve diameters and realised after the test that the rudder angle was limited. Now it should be tighter.
"Classic", "modern" or "freestyle" are the interior finishes of the Aquanaut. Our test boat falls under the "modern" category, of which the shipyard says: "The modern style is impressionistic, but also abstract and makes use of modern materials." Everything is neat and tidy.
In three cabins (extra) and two bathrooms, space and especially stowage space are not neglected. The headroom is just right and the galley leaves almost nothing to be desired. Feel good on and below deck. The engine and technical room is clearly structured and there is almost nothing to prevent daily checks or servicing.
The fuel pre-filter is criticised: no water alarm sensor; the shipyard wants to think about the positioning of one or other part.
The driving position offers plenty of space and is puristically equipped, with navigation information provided by the electronics. The quality is right all round, as almost everything, apart from the stainless steel, upholstery, sandblasting, engines and electronics, comes from our own factory.
The extensive standard equipment deserves praise, and as usual you can customise your boat with the help of the accessories list.
Our conclusion: The Andante 438 AC can be described as an all-round successful boat and the space and roominess are almost generous. As the boatyard manufactures almost everything itself, with a few exceptions, the quality is just right. Of course, the waters around Grou have not revealed how the boat behaves at sea in wind and waves. But otherwise it lives up to its name.
Data sheet: Aquanaut Andante 438 AC
Shipyard: Aquanaut
Type designation: Aquanaut Andante 438 AC
CE category: B - Outside coastal waters
Material of hull and deck: Steel
Length: 13,15 m
Width: 4,30 m
Displacement: 18,00 t
Price: 383.240,00 €
