Aluminum boats of the Ob series occupy a special place in the history of domestic water-motor sport and amateur fishing. OBE 4 It was a logical development of the line, inheriting the legendary indestructibility of the hull, but with a more rational layout of the cockpit, and for many aquatic motors, this project remains the benchmark of reliability, despite the solid age of the structure.
In this article, we will discuss in detail the technical nuances faced by the owner when buying or operating such a boat. marine stability It's still a model that's respected, and the trade-offs that have been made to improve comfort, and understanding the physics of the body's behavior on the wave is critical to safe driving.
Many believe that the time of such “buckets” is long gone, but the rising prices of modern composite and imported analogues are returning interest to the Soviet heritage. Aluminum alloy The D16T, which is the body’s original shape memory and maintainability, are the factors that make the boat relevant today, requiring only a competent approach to modernization.
History of creation and design features
The fourth modification was developed taking into account the accumulated experience of using previous versions, especially the Obi-3. Engineers of the Novosibirsk Aviation Plant needed to eliminate the main complaint of users - cramped and low landing. hull-width And then we had a modified transom geometry, which allowed us to install more powerful outboard motors without the risk of losing stability.
Structurally, the vessel is a welded structure of sheet aluminum. duraluminia It allowed you to reduce weight while maintaining high strength, and unlike earlier versions, it redesigned the set system, which has a positive effect on the stiffness of the bottom, but like any metal, the material requires corrosion protection, especially in welds.
⚠️ Attention: When buying a used boat, be sure to check the condition of the welds in the area of the zygomatic bends. This is where fatigue cracks most often occur due to constant shocks to the wave.
The deck design deserves special attention, and unlike its predecessors, it has expanded its jars and improved access to the bow locker. Tightness The compartments were elevated, which became an important safety factor, but you don't have to rely on the buoyancy of the hull when you're excited, you have to have life jackets.
Technical specifications and dimensions
For the correct selection of the engine and trailers, it is important to know the exact parameters of the vessel. OBE 4 It's a small pleasure boat, and it's designed to be glided, but it requires a power plant to go into mode, and it's a 30-40 hp engine, but it's also more powerful than that.
The table below contains the basic data-sheet figures that will help you navigate in size:
| Parameter | Meaning | Unit of measurement |
|---|---|---|
| Longest length | 4300 | mm |
| largest width | 1600 | mm |
| Height on midship | 700 | mm |
| Load capacity | 400 | kilogram |
| Passenger capacity | 4 | man. |
It is important to note that the real loading capacity It can vary depending on the condition of the hull and the amount of equipment installed, and overloading the boat leads to a buoyant nose and a decrease in speed. Engine bay. designed for standard lower unit, but when installing powerful 4-strokes may require modification of the suspension cutout.
The weight of the hull in running order is about 160-170 kg. This is enough for manual transportation, so the presence of a trailer is almost necessary. When calculating the load on the trailer, consider the weight of the engine, fuel, anchor and crew. Balancing The trailer should be ideal to avoid vibrations when transported along the track.
When calculating your load capacity, always keep a 15-20% margin of data-sheet figures. Real wave and fuel can significantly change the boat's differential.
Driving and handling
On the water, Ob 4 exhibits behaviors that are typical of narrow-hulled glissers with a keeled bottom. It confidently cuts the wave, but has a tendency to yaw at high speed, especially in lateral winds. keel Or transom plates.
The minimum speed for going to the planing with one person on board and a 30 hp engine is about 25-28 km / h With full load, this threshold increases. Angle of keeliness The bottom is soft, but it increases the water resistance, so you can't expect a stock boat to record speeds, it's more of a reliable worker than a racing projectile.
⚠️ Attention: When running at full gas, watch for the cockpit splashiness. The high side protects well, but the oncoming wave can fly through the nose if the boat goes with a defferent on the nose.
Manageability is directly dependent on motor takeaway, and the factory recommendation for a lower unit installation is often conservative, and many owners find, through experimentation, the optimal position in which to put the device in place. lift lower unit helps to put the boat on mode faster, but excessive removal can lead to cavitation and overheating of the engine.
Typical problems and corrosion
The main enemy of any aluminum boat is electrochemical corrosion. Despite the use of the D16T alloy, which is quite resistant, in places of contact with water and especially with wandering currents, there can be centers of destruction. submersible and the area around the fasteners.
Owners often experience leaks on the zygomatic bend, which are the result of metal fatigue and vibrations, and repairing these places requires clean metal and high-quality argon welding, and simply sealing the crack is a temporary solution that can lead to more serious consequences on the water. Regular examination The bottom after each season is mandatory.
Another problem is the attachment of cans and rundooks, factory bolts unwind or rust over time, and it is recommended that you replace the standard fastener with stainless or galvanized with plastic washers to prevent direct contact of metal with aluminum, which will prevent the formation of galvanic pairs.
How to deal with the “sweating” of aluminum?
Aluminum doesn't rust like steel, but it oxidizes. A white coating is an oxide film that can be removed with special polyroles for aluminum, but it's best to just thoroughly wash the boat with fresh water after each exit into salt water or a muddy body of water.
Tuning and modernization of the boat
There's no limit to perfection, and Ob 4 is no exception. pulp It's a long tiller, or a remote control, which makes it much more comfortable to drive, especially on long-distance crossings, and it's also often lighting and navigation.
Many owners install windshields from other models or make them themselves from Plexiglas, which makes you feel comfortable even in the headwind. soft-seat Aluminum frame, as regular hard cans quickly tire the back.
Here is a list of popular improvements that really improve the operation:
- 🚀 Installation of transom plates to improve the output for planing and stabilization of the course.
- ⚓ Organization of an anchor box in the nose with convenient access.
- 💡 Installation of LED lighting of the cockpit and navigation lights with low power consumption.
- 🎣 Installation of holders for rods and brackets for sonar / navigator.
When carrying out any work on drilling the body, remember waterproofing. All holes should be thoroughly smeared with a sealant before installing the fastener. Isolation. It must be reliable, otherwise the water will gradually break the connection and get inside.
☑️ Checklist before season
Comparison with competitors and analogues
In today’s market, Ob 4 competes with models like Crimea, Voronezh or more modern Salutes, with the Ob’s main advantage being its time-tested design and availability of parts. Repairability This boat is higher than many modern analogues of thin aluminum.
However, compared to new developments, the Ob loses in ergonomics and weight. Modern boats are often lighter and have more elaborate crewing schemes. But when it comes to price/quality/resource ratios, the Soviet classics hold the mark. Liquidity The secondary market of such boats remains consistently high.
When choosing between a rebuilt Obue and a new budget boat, weigh your priorities. If you want a workhorse for fishing in trophy areas where you can scratch your bottom, the Ob is a great choice. For family walks in the reservoir, it may be worth looking at more modern and comfortable models with soft chair suspension.
The Ob 4 is the choice of a pragmatic who values reliability and maintainability over modern design and light weight.
Frequently Asked Questions (FAQ)
What is the maximum speed to be reached on Ob 4?
With the engine 30-40 hp and one driver speed can reach 40-45 km / h With full load speed drops to 30-35 km / h Much depends on the state of the bottom (fouling), screw and engine setting.
Should I paint an aluminum boat?
Painting is optional, but preferably to protect against fouling and electrochemical corrosion, using special soils for aluminum (e.g. VL-023) and enamel, often owners simply polish the metal.
Can I put on the Ob 4 engine with a capacity of 50 hp?
The boat's trawler is designed for engines up to 40 hp. Installation of 50 hp is possible, but requires strengthening of the transom and very careful operation. This can be unsafe and violates the passport requirements of the GIMS.
Where to find the plans and diagrams for the boat Ob 4?
Original drawings can be found in the archives of the magazines "Boats and Yachts" for the 70s or on specialized forums of water engines in the documentation section.