GB2493424A - A floating position marker - Google Patents

Abstract

A floating position marking device comprises a waterborne float 1, an underwater attachment means 3 and 4, and a heavier than water sinker 5. The device is arranged such that the float holds its position on the water surface 6 vertically above the sinker over a range of water depths when the sinker is resting on the bottom. The floating position marking device may be used in swimming pools and open waters. The floating position marking device may have options enabling it also to indicate the depth of water, water current speed and direction, and wind speed and direction. The floating position marking device may be made in various sizes. Smaller sizes may be light enough to be transported and deployed as required by tidal conditions, or at specific swimming or sailing events.

Description

1LOATING POSITION MARKER This invention relates to a floating position marker.

Existing floating position markers, often known as buoys, are used to mark channels, hazards and moor boats. They also provide a floating refuge.

The floating position markers are secured to the bottom of a waterway by an anchor or a heavy weight that connects to the buoy or other marker floating on the surface1 by means of a rope or a chain. (I the water level changes, then the buoy is liable to become submerged lithe connection is too short, or to drift from its set position if the connection is too long. A heavy chain at the bottom end, of a length equal or greater than the maximum change in water level, can minimise this effect, but it has to be matched by a buoy of sufficient buoyancy to lift the chain when the water level is highest.

*:*. Another means to mark the position of a channel is by posts fixed into *r"i the water bed, The posts have the advantage of being capable of being marked with water depths. The posts have the disadvantage of needing to be * high and strong enough to be visible when the water is at extremes of level, : * whilst not being a hazard causing, for example, an accidental collision. Much work is required should the position of the channel change and the poles required to be re-cited.

The device is also useful to mark the depth and position of a wreck or other submerged obstruction in a waterway. Another use of the device may be to ascertain the depth of water for a line angler1 who may then set their bait at the correct depth above the bottom for a fish Species to be targeted.

In swimming pools, the depth of the water may be indicated around the edge, the depth changing due to the swimming pool having a sloping bottom, or having a moveable bottom. Actual Jane positions are sometimes marked on the bottom of the pool. Such markings are unsuitable for those who do not open their eyes under water. Actual lane positions may also be marked by floating lines, but this is often inconvenient for swimmers. Floatation aids are either in use by swimmers, or they may drift in the way of swimmers.

It is an aim of the present invention to obviate or reduce the above mentioned problems.

Accordingly, in one non-limiting embodiment of the present invention there is provided a floating position marking device comprising a waterbcjrne f3oat, an underwater attachment means, and a heavier than water sinker such that the float holds its position on the water surface vertically above the sinker * over a range of water depths when the sinker is resting on the bottom.

The floating position marking device may be one in which the :. underwater attachment means is an elastic part. Alternativecy, the floating * *: position marking device may be one in which the underwater attachment means includes a flexible non-extending part.

* :" The floating position marking device may be one in which the waterborne float has a buoyant part under the water, and an upper part which is visible above the water level and which is provided with markings indicating water depths. The markings may be one or more of line markings, colour markings, alphabetic or numeric markings, or pictograms.

The waterborne float may have a light for indicating a shallow depth of water.

The waterborne float may include audio means for emitting an audible signal to indicate a shallow depth of water.

The waterborne float may include an electronic depth sounder.

The waterbome float may include a pulley that rotates according to the water depth.

The floating position marking device may be one in which the sinker has magnetic properties of attraction when rested on a magnetic body.

The floating position marking device may be one in which the waterborne float is used to indicate deep water, or alternatively to indicate shallow water. The waterborne float may be used to indicate a position in a water sport event, or it may be used as a refuge for swimmers. The waterborne float may contribute to safety on or in the water.

The floating position marking device may form part of a flood warning system.

The floating position marking device may include electrical generation equipment working as a result of changes in water level.

*.... The floating position marking device may comprise a shaped float that rotates in a current to an angle indicating the direction of the current.

The floating, position marking device of the present invention may be such that in use the waterborne float submerges to different depths, thus indicating the depth of water.

The floating position marking device may enable lightweight fastenings to the bottom of the waterway, and reduced size of buoys to be used.

Different water depths at which the devices are designed to work may be due to tidal changed, currents, flood, canal or lock levels, the effect of winds, etc. The floating position marker may be used to mark depths, and also courses in swimming pools. It may also provide a temporary float for swimmers to rest, instead of having to swim to the side of the swimming pool.

As the wAter depth changes, so the force in the connection to the bottom changes, and the floating position marker becomes more submerged or less submerged. In the case of an inextensible connection to the bottom, this submersion will be the same as the change in water depth. In the case of an elastic or sprung connection, the amount of submersion will depend on the elastic qualities of the connection and the change of buoyant qualities of the * marker. The vertical sides of the floating position marker may have indicating means for recording the amount of submersion by direct observation, Sensors on the floating position marker may enable the amount of submersion to be : ** seen, heard or recorded remotely, or t be shown in darkness by light *: emitting means on the buoy. Such recordings may be related to the change in water depth, or to actual water deØth if the floating position marker has been calibrated. It is important to note that the buoyant qualities of the floating position marking device are dependent on the density of the water (which varies according to temperature and salination etc.) and of the change of the volume displaced by the floating position marking device (which may vary if its cross section changes according to its depth of immersion).

The fastening to the bottom by an extendable means also enables the depth of the water to be indicated whilst the float is on the surface. A floating position marking device having a submerged float, having an extended vertical stem that extends above the surface, also has advantages, especially in rivers where an upstream indicator of high water levels can be used to instigate a flood alert to areas downstream. Electrical or electronic switches or transducers can be used to detect the water level on the stem. Their outputs.

can be scanned from a remote station by telemetry means, or the outputs may operate light and/or Sound emitting devices.

The extension of the elastic connection will exert a downward force on the float depending on its extension and thus the water depth. According to the depth of the water, so the float will be pulled to different depths in the water. These equivalent water depths can be marked by colour bands, by numbers, or by pictograms, The float may have various shapes in order that it presents a different appearance according to its water line and the depth of the water underneath.

: ,-Larger areas of buoyant materials at different vertical heights on the float can cause the float to have preferred water levels at the positions of those areas.

If the water depth and buoyancy are such as to cause the float to lift the sinker, then the sinker may be connected to a further one by more elastic or by a rope or chain to a more secure fastening to the sea bottom.

A typical 3mm diameter shock cord with a natural length of 1 metre extends 33% for 200gm, 800/n for 400gm, 110% for 500gm, 140% for 700gm, and 160% for 900gm. Additional loads do not extend the elastic very much more, the elastic being fully extended at around 190% (2.9m) for 2kg. These figures illustrate that an uneven distribution of buoyancy up the float is required in order for its submersion to be linear with extension. Other elastic or spring connections may provide advantages where greater water level variations occur. Where the extension approaches the full elastic extension, the float can have a low buoyancy upper section so that the float no longer exerts higher forces that might lift the sinker. In this section of the float, the water level markers may be the same distance apart as the increases in water depth and the buoyancy of the float remains less than the sinker weight.

in the case* where a rope passes over a pulley on the float that is visible above the water, the rope itself can be marked with bands of different colour, thus providing a direct correlation between the rope colour and the depth of water (that is the length of rope beneath the pulley). One disadvantage of a rope and pulley system is that the length of the rope must cater for the maximum depth, and if the water depth should decrease to less : * than half the maximum, then the depth of water and the position of the float will no longer be accurate.

An elastic fastening can be used for a variation of depth greater than a 3:lratio.

The means of measuring and displaying the water depth may also include electronic depth sounder devices and pressure measurements from the bottom.

An alternative for keeping the float in position above the sinker may include means in the float that keeps the line to the bottom taught by a spring means or by mechanical means, such for example as an electric motor and winding device that stores the slack on a bobbin. The connecting line can be light, even less dense than water in the case of some polymers such for example as polypropylene.

Floating position marking devices according to the present invention may be used in swimming pools, rivers, lakes estuaries and coastal waters.

The portability of the floating position marking devices may extend function for temporary use during water sports events such for example as races or regattas, and also for use as safety markers. When deployed by boatmen, the floating position marking devices can be in positions which are selected by reference to the positions of underwater features indicated on the vessel's depth sounding equipment1 or by using a lead line. The calibration of any depth markings on the floating position marking devices can be checked when selling out and at intervals.

The floating position marking devices can be used as semi-permanent *:*** channel and hazard markers. A floating position marking device may be used as a mooring marker. The floating position marking device may then be a point for attaching a slack rope to the underwater anchoring means during a day trip from the mooring.

If the floating position marking device is in a current or in a high wind, then this may be indicated by a lean on the normal vertical part. The form of the sinker weight may be varied according to the use and the bottom, for example whether the bottom is hard and level, rocky, sandy, gravely: muddy, magnetic (as would be the case with a submerged wreck of a steel ship or mine) etc. The sinker weight may have a release rope or features to enable the sinker weight to be removed using a trawl device in the event that the sinker weight cannot be removed by lifting the float.

Floating position marking devices according to the present invention may have adequate instructions for use and provide those specifications and warnings necessary to ensure that the floating position marking devices are safely used.

Embodiments of the invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figures Ia, lb. lc, id and le show apparatus of the present invention in use; * . S S. Figure 2 shows static forces on the apparatus of Figure la; Figures 3a and 3b illustrate upward forces applicable to the apparatus of Figure Ia; and : *** Figures 4a and 4b illustrate downward forces applicable to the apparatus of Figure la.

Referring to Figure la, there is shown a floating position marking device comprising a waterborne float 1 which is attached at point 2 to underwater attachment means in the form of a length of elastic 3 and an 9.

inextensible flexible member 4. The elastic 3 is attached via the inextensibte flexible member 4 to a bottom of a waterway with a water sinker weight 5. A water level 6 is shown between markings 7 and 8 on the float 1.

Figure lb shows part of the floating position marking device 1 shown in Figure 1. In Figure lb, bait 11 is attached to a hook and line 12 as shown to attractafish 13.

Figure ic shows the inextensible flexible member 4 of Figure Ia provided with a water sinker 14 instead of the water sinker weight 5. The water sinker 14 is in the form of a magnet for attaching itself to a steel wreck as shown.

Figure ld shows the magnet 14 operating on a fixed magnetic plate 16 as might occur at the bottom of a swimming pool. In this case, the magnet 14 may be used for more than one of the fixed magnet plates 16 which may be at predetermined positions for example predetermined positions in a swimming pool.

Figure le shows a floating position marking device having a vane 17 : which is rotated to align with a current direction 19. The vane 17 is provided with markings in the form of arrows 20 for indicating the depth of the water 21.

: *.. Figure 2 represents a simplified representation of the static forces :3 pertaining to Figure la. In Figure 2, there is shown a force F present in the elastic 3 causing the elastic 3 to be extended from its natural length by a distance dX and also Causing the floating position marker to be submerged more than its normal floating depth 7 by a distance dY.

Figure 3a shows the floating position marker replaced by an upward force F. Figure 4a shows the elastic replaced by a downward force F. Figure 3b shows a graph of the upward force F as a function of the extension of the elastic dx.

Figure 4b shows a graph of the downward force F as a function of the submersion of the floating position WY.

Since the apparatus is in static equilibrium, then the upward force F in Figure 3b is equal to the downward force F in Figure 4b. Thus, for any change in water depth from 22 on Figure 2 to 23. the force F on Figure 3b will show that the extension dX will change from 31 to 32. Similarly1 the same change in water level will relate to the same change in force F in Figure 4b, causing the depth of submersion of the floating position marker dY to change from 33 to 34.

A simple system as shown relates to linear functions of force F against the elastics dX in Figure 3b, and a linear function of force F against submersion dY in Figure 4b (an approximation for a floating position marking device of constant cross section).

4. The different slopes of the two graphs cause a difference in the distances 31 -32 and 33-34. If the slopes were identical than the change in *e..

water depth 35-36 would be shared equally between the distances 31 -32 and 33 -34 but in the case shown (for places having a large change in water depth) it is convenient to have most of the distance 35 -36 take up by the extension of the elastic 31 -32 so that the floating position marking device needs only to accommodate the smaller change 33 -34.

If the graphs of Figures 3b and 4b are shown with sufficient accuracy.

then the value of the force F can be derived for different depths mathematically. However, a calibration of the floating position marking device in water of the target salination could be made to establish the water level marks on the floating position marker corresponding to different depths, or the floating position marking device could be deployed in a known water depth and then be marked accordingly.

A single elevation is shown in each of the Figures, as would suffice in the case that each of the float and sinker weight components were cylindrical about a vertical axis. In situations where high current may deflect the float from its position vertically above the sinker weight, it may be desirable to minimise the effect by shaping those parts of the float that are under the water as shown in Figure le where the current direction 19 aligns the vane 17. The float will turn on its flexible connection to present the least resistance to the flow of the current and the vane 17 will align with even slow water currents. Arrows on a part of the vane above the water will then point in the upstream direction. In a windy location, it may be necessary to reduce the * ,.. amount of the vane 17 that is above the water level. Wind conditions often change from place to place near a coast and sailors would find it useful to have wind velocity and direction indicators. These could be provided by mounting a windsock on each floating position marker.

It is to be appreciated that the embodiments of the invention described above with reference to the accompanying drawings have been given by way of example only and that modifications may be effected. Individual components shown in the drawings are not limited to use in their drawings and they may be used in other drawings and in all aspects of the invention. S. * * p. * *5

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Claims (1)

1. <claim-text>CLAIMS1. A floating position marking device comprising a waterborne float, an underwater attachment means, and a heavier than water sinker such that the float holds its position on the water surface vertically above the sinker over a range of water depths when the sinker is resting on the bottom.</claim-text> <claim-text>2. A floating position marking device according to claim 1 in which the underwater attachment means includes an elastic part.</claim-text> <claim-text>3. A floating position marking device according to claim 1 in which the underwater attachment includes a flexible non-extending part.</claim-text> <claim-text>4. A floating position marking device according to any one of the preceding claims in which the waterborne float has a buoyant part under the water, and an upper part which is visible above the water level and which is provided with markings indicating water depths. *</claim-text> <claim-text>5. A floating position marking device according to claim 4 in which the ** * markings are tine markings. * *. * . * **s.</claim-text> <claim-text>* 6. A floating position marking device according to claim 4 in which the markings are colour markings.</claim-text> <claim-text>7. A floating position marking device according to claim 4 in which the markings are alphabetic or numeric markings.</claim-text> <claim-text>8. A floating position marking device according to claim 4 in which the markings are pictograms.</claim-text> <claim-text>9. A floating position marking device according to any one of the preceding claims in which the waterborne float has a light for indicating a shallow depth of water.</claim-text> <claim-text>10. A floating position marking device according to any one of the preceding claims in which the waterborne float include audio means for emitting an audible signal to indicate a shallow depth of water.</claim-text> <claim-text>11. A floating position marking device according to any one of the * preceding claims in which the waterborne float includes an electronic depth sounder. * . * .</claim-text> <claim-text>* *;: 12. A floating position marking device according to any one of the * ** preceding claims in which the waterborne float inctudes a pulley that rotates **** *...: according to the water depth.</claim-text> <claim-text>13. A floating position marking device according to any one of the preceding claims in which the sinker has magnetic properties of attraction when rested on a magnet body.</claim-text> <claim-text>14. A floating position marking device according to any one of the preceding claims when forming part of a flood warning system.</claim-text> <claim-text>15. A floating position marking device according to any one of the preceding claims and including electrical generation equipment working as a result of changes in water level.</claim-text> <claim-text>16. A floating position marking device according to any one of the preceding claims and comprising a shaped float that rotates in a current to an angle indicating the direction of thecurrent.</claim-text> <claim-text>17. A floating position marking device substantially as herein described with reference to the accompanying drawings. * . * * * *e. * * ** * * * * * *</claim-text>