JETCRAFT. Водомёт. Водомётный движитель. Теория.

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     Marathon Marine - web.  Cтатья очень доходчиво рассказывает НА ЧТО ОБРАТИТЬ ВНИМАНИЕ при покупке лодки или водомётного катера.

NEW. Росомаха (img) русский конкурент Harbercraf / Jetcraft


Byuer Guide Руководство покупателя


Фотографии с выставки "MIBS 2009"

Закон и катер. Постановка на учёт катера со стационарным двигателем.


дюймы в сантиметры

Словарь ( Dictionary ).

Сравнить ( Compare Boats )

Теория ( Theory ).


Форумы на тему... с переводом.



1875 J-Max White Water (img)


2075 White Water



1875 J-Max XS (img)


2175 XS Фотографии с выставки "Охота и рыбалка - 2008"


Marathon Marine and Northwest Jet Boats (link)


PHANTOM Jet Boats (link)


RiverPro®. (link)


North Silver PRO 675Jet lnk


Росомаха (img)


Tom 525. Томь 525.


Коллекция ссылок на тему: водомёты для судов (Links).

5 White Water test drive

Курс доллара









Boat Materials: Aluminum versus Fiberglass Материалы для катера

The boats in general section applies to any boat. Why should you buy welded aluminum?





Pound for pound as stiffas steel


Low. Needs reinforcement



35% of steel

Low. Medium

Strength to weight Ratio




Corrosion resistance in Salt Water




Osmosis Risk



Impact Resistance

Varies, depending upon


grade (see below)

Brittle, very little. Once


hit osmosis sets in

UV Resistance


Low - needs additives



As can be seen from the above, aluminum is superior as a construction material to


fiberglass for structural components as:


It has high impact resistance


There is no osmosis risk


It has high rigidity


It is lighter.


It has a high strength to weight ratio.


Cost differences between glass and aluminum


Cost is a misleading comparison. Although pound for pound, aluminum is more


expensive than fiberglass, one needs substantially more fiberglass to obtain an equally


strong hull. For example, it takes about a 3,000- 4,000 lbs. of fiberglass to equal the


strength of a 1,000 pound aluminum hull. There are a few glass boat builders who build


this strong a hull. When you check their prices you will find they cost substantially more


than the aluminum hull.


Secondly, although the glass hull may initially be as strong, it will not have anywhere


near the impact resistance of aluminum.


Thirdly, although they may be able to handle an initial impact, the collision creates stress


cracks which allow osmosis to set in and the hull will deteriorate over time. Sun, stress


cracks and osmosis will all wreak havoc over time. Therefore, over time fiberglass’


strength deteriorates.


Fourth, all the added weight on the glass boat creates a severe performance, fuel


consumption and power plant penalty. To push the extra weight of a glass boat a larger,


heavier more expensive engine is required. In a bit of negative circle, bigger engines need


to be even bigger to push their own weight. Bigger engines burn more fuel which requires


even more weight for fuel storage and therefore an even bigger engine. More weight


makes for slower planning and more wallowing in big water. Ask any heavy duty glass


boat owner about the performance and operating cost of their boat.


Types of Aluminum


All welded aluminum boats are not created equal. Builders used different techniques and


different aluminum in their hulls. The following tells you what to look for:



5052- H32

 (подробнее: 1  2)

5086- H32



Impact resistance


Soft, dents easily





Tensile strength -


(where the metal breaks)




Tensile strength - Yield

(point to which metal bends and will not


spring back)





Ducility (ease of bending)

Easy Care must

be taken


Limited bending


Where used in Marathon








side trays




Based on 1⁄4" thickness


Figures are minimums. Actual samples will vary. 5052 tends to have the highest




From the chart above one can see why Marathon uses 6061 for the rub rail (gunwale) joint


components and 5086 for bottoms. These are structural components that hold the boat


together. As boat powers through the water it (flexes). (Therefore) you want strength,

                                                                        (гнуться). (Следовательно)

hardness and little bending ability in your structural components. It is the structural


components that allow the boat to keep its integrity.


How does this affect you? Ask what is in the boat.. See how it is built. Ask what


materials go into it. Why ask? Some boats use 5052 in their bottoms. Others use minimal


thicknesses and designs in their stringers. If you are a light duty user, it probably does not


make much difference. However if you (put your boat through its paces) and push it a little,

                                                         (подвергнуть испытанию/ «прощупать»)

you will see the differences show up over time as one boat will develop cracks and the


other will not.


Material Thickness


This paper is talking about (heavy gauge) welded aluminum boats or what some call plate

                                           (тяжёлого размера / калибра)

aluminum. The bottoms in these boats range (from 3/16” to 1⁄2”). Although some builders

                                                                            (от 4,76 мм до 12,7 мм)

in this class use thinner bottoms in this class, most quality builders do not. Heavy gauge


welded boats usually see heavy use and requires the strength.


We are totally excluding boats of the light duty welded aluminum class, which are


basically a small step up from riveted boats. These builders use thin bottom material,


often 5052 and (reinforce) their boats completely differently than heavy gauge builders.

                       (укреплять / армировать)

Secondly, look at the material thickness and listen to the (explanations) as to what is used


and why.


Boats: What to Look For. НА ЧТО ОБРАТИТЬ ВНИМАНИЕ при покупке лодки.




Welded Boats in General:

Сварные лодки в общем

Our Bias

Наши предпочтения

Shop for a Manufacturer First


Look in the used boat ads


Judging the Production Staff


Manufacturer Reputation


Buying a Welded Boat for the First Time


Know the Boat you want


There is no Perfect Boat


Take a test ride.


Acceleration out of the hole


Bottom Width and Engine Size and Type.


Turning ability.


Stability at Speed: Porpoising versus bow down  Дельфинирование.


The Hook.


Spray Line?.


Boat Materials: Aluminum versus Fiberglass . Материалы для катера


Cost differences between glass and aluminum .  Сравнение стоимости стекловолокна и алюминия.

Types of Aluminum. Типы алюминия.


Material Thickness


A Word about Welding


Suck marks, caterpillar tracks


Folded, ‘Origami’ Construction


Hull Design


Delta Keel.


Deadrise (Vee)


Planing Hull Bottom Types Корпус с дном плоского типа


Constant deadrise V (including modified V hulls)


Flat bottom hulls (8 degrees deadrise or less)


Bow Entry Types. Тип носа катера


Shallow Entry


Sharp Entry


Radius Bottom Круглое дно.


Lift Forces Explained.


Lateral Stability During Planing Turns


Bottom Shape and Jet Intake


Planing Ability


Reverse Chines


Bottom Width: Flair is not everything


No Trim.


Hull Construction Standards


Shallow Water Operation


No Exposed Drive




Thrust line and Center of Gravity In line


Propeller Torque is Different than Impeller Torque


Propulsion Resistance.


Power Plants

Силовая установка.

Derived from Impeller Curves.


RPM Curve Derivation




Hull Resistance.

Boat attitude..


Jet Drives


How jets work .






Cut, Speed and Load


Wear ring.






Hard Anodized.


Cavitation .






Mixed flow


Axial flow.


Outboard jet:


Inboard jets:


So, what is the best jet?






Jet Diagnosis...


Rattle at Idle (V8 boats)


Speed too low for a Given RPM.


Poor acceleration or ‘holeshot’, combined with high top end




Porpoising .


Chine walk: 9


Ram effect .


Static thrust:


Водомётный движитель. ТЕОРИЯ.


Адрес для переписки:

Spiridonov S. E.

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JETCRAFT. Водомёт. Водомётный движитель. Теория. Лодка. На что обратить внимание. Руководство пользователя. (Boats: What to Look For . Buyer guide)