referring to fig3 and thereafter , the embodiments of the present invention will be described . terms “ key module ” and “ base module ” as used herein are defined in prior section . a keyboard 10 shown in fig3 is a first embodiment of the present invention . the keyboard 10 is generally comprised of a rectangular base module 11 and a t - shaped key module 12 . the base module 11 defines a bay area across most of its upper surface shaped to fit the key module 12 when it docks into the bay 11 in manufacturing process and subsequent events of maintenance at home or office . the key module 12 contains no electronic circuitry and is self - sustainable in and out of the keyboard to maintain its integrity . meanwhile , even if the key module 12 is removed , the base module 11 houses the supporting components for the operation of the keyboard 10 in a water resistant manner . as a matter of practice , the base module 11 will at least have an electrical circuitry / pcb component 13 as shown in fig9 . the electronic circuitry 13 is used for decoding the signals of the keystrokes by a computer user to provide the decoded signal to the computer through a wired or wireless connection . from top to bottom , the components of the keyboard 10 will include a top key - holding plate 14 for supporting multiple keycaps 15 in their free vertical movements within a limit provided by a retaining means not shown , a key - actuating mechanism 16 in a resilient sheet formed with upward domes for biasing the keycaps 15 at a raised level , the electrical circuitry membrane / pcb 13 , a bottom holding plate 17 , upper and lower enclosure halves 18 and 19 , which allow the key - actuating mechanism 16 to be connected to the keycaps 15 of the key module 12 mechanically but not permanently as shown in fig9 and 16 . the upper enclosure 18 corresponding to the hard plastic casing of a keyboard for a traditional desktop computer may be grouped into the base module 11 as in fig9 or a key module 812 as will be described with reference to fig1 . the key - actuating mechanism 16 comprises a rubber dome and / or a spring integrated into each key 15 for providing a feedback . these mechanisms both provide the right feel to the user and reposition the key 15 after it has been released . depending on specific manufacturing or assembly needs , the key - actuating mechanism 16 may be grouped into either the base module 11 as in fig9 or the key module 12 as will be described with reference to fig1 and 16 . fig3 shows the keyboard 10 having various arrays of rubber domes 7 formed on a single elastomeric sheet in spaced groups of various inputs such as alphabets , numbers , and software functions , etc . drain holes 20 serve as a water channeling mechanism at one end of the keyboard 10 ; the whole keyboard unit 10 is elevated on one side 21 , causing the side 22 with drain holes 20 to be lower . water - sealing mechanism 23 around the inside rim 24 of the key bay 11 is shown . rubber strips or sheets are preferred material for achieving the water sealing , without blocking the drain holes 20 on the lower end 22 of the key bay 11 . the key module 12 has tabs 25 at its four sides , which can be snapped in to grooves 26 on the inside rim 27 of the key bay . each tab 25 is u - shaped in cross section and ends with an outer end 28 extending perpendicularly up to the level of a top surface 29 of the key module 12 . the tab end 28 of the base module 11 has at its outer sidewall a laterally extending protrusion 30 adapted to be received in a lateral groove 31 formed in the rim 27 of the base module 11 . when the key module 12 is introduced into the base module 11 , the four side tabs 25 are resiliently flexed away from the rim 27 of the base module 11 and immediately return to their normal positions and then snap into the grooves 26 to secure the two modules 11 and 12 to each other . in the event of maintenance , the tabs 25 may be flexed out of the grooves 26 using a simple prying edge in order to release the key module 12 from the base module 11 for cleaning or other purposes . fig4 shows a notebook / laptop computer 100 having a monitor 101 hinged to a system unit 102 , which comprises a base module or bay 111 on the top surface . a key module 112 is shown removed from the bay 111 to expose a water sealing mechanism 120 applied to around the inside edge of the bay 111 . the key module 112 has two opposite side edges 113 for sliding engagement with opposing guide rails 114 formed in an inward rim 115 of the bay 111 . in fig5 , a keyboard 200 according to another embodiment of the present invention encompasses the type of key module where it can be broken into sub - modules 212 - 215 , or it is of a foldable type . fig6 shows another notebook computer 300 having a system unit 302 wherein side drain channels 320 function as the water channeling mechanism . the notebook computer 300 has a base module or bay 311 in which a key module 312 is removably secured by snap tabs similar to the tabs 25 of fig3 embodiment . the notebook computer 300 is similar to the notebook computer 100 of fig4 in that the water - sealing mechanism 120 is also applied to around an inside edge of the bay 311 although it is not visible in fig6 . the system unit 302 has four corners at rear ends 321 and front ends 322 . the drain channels 320 extend at least portions of the opposite side edges of the system unit 302 to communicate the interior of the bay 311 to atmosphere of the computer 300 at openings located at the front ends 322 . with the system unit 302 tilted up a little at the rear ends 321 relative to the front ends 322 containing the drain holes , any possible liquid spillage through the key module 312 will gravitate towards the drain channels 320 ; causing the liquid to flow out of the key bay 311 . to tilt the rear ends 321 up , traditional pullout tabs 323 may be installed at the bottom of the system unit 302 . alternatively , the base module 311 containing the system unit 302 of the computer 300 may be manufactured to be thinner on the front ends 322 of the drain channels 320 and thicker on the other ends 321 , to create the required tilt for liquid to flow downwards . in fig7 , a keyboard 400 according to another embodiment of the present invention has a rectangular base module 411 , which defines a rectangular bay over its entire upper surface . water channeling mechanism 420 in the form of drain holes is formed about a lower end 422 of the keyboard 400 facing the front and sides thereof . the keyboard 400 has a water - sealing mechanism ( not shown ) similar to the mechanism 23 of fig3 embodiment except that it now has four sides different from the eight sides because a key module 425 is shaped after the base module 411 to mate at four sides . fig8 shows a keyboard 500 having a single base module 511 that is subdivided into multiple bays . the sub - bays include a primary bay 511 a for seating an alphanumeric key module 512 a , a side bay 511 b for seating a numeric key module 512 b , and a rear bay 511 c for releasably holding a customizable key module 512 c , etc . the key modules 512 a , 512 b and 512 c has two opposite side edges 513 a - 513 a , 513 b - 513 b and 513 c - 513 c for sliding engagement with opposing guide rails 514 a , 514 b and 514 c formed in inward rims 515 a , 515 b and 515 c of the sub - bays 511 a , 511 b and 511 c , respectively . then , they can be secured to each other by employing a latch - hinge mechanism . for each sub - bays , a rectangular water sealing mechanism is installed although only two of them are shown at 523 a for the primary bay 511 a and at 523 b for the side bay 511 b . fig9 is a schematic drawing in an exploded cross sectional view of the first embodiment of the present invention of fig3 wherein top drawing shows the key module 12 separated from the bay 11 according to the present invention . this is the desktop computer keyboard construct . fig9 bottom drawing shows the key bay 11 having beneath it two layers of water sealing mechanism used in a traditional type keyboard construct : one above the holding plate , one ( extra layer ) below the holding plate . the water - sealing mechanism 23 may be formed by this three - layer plate bearing against a shoulder 24 a formed around the inside rim 24 of the upper enclosure 18 of the base module 11 . or it may be a gasket secured firmly between the shoulder 24 a and the key - actuating rubber dome 16 . fig1 is an exploded view of a notebook / laptop computer 600 having a monitor 601 hinged to a system unit 602 , which comprises a bay opening 611 on the top surface with a key module 612 removed from the opening 611 to show the relative vertical position of a water sealing mechanism 623 . fig1 to 14 show the various methods of mounting the key module to the bay / base module . as in fig1 , the mounting may be achieved by using screws in the top - down orientation of a keyboard 700 having multiple sub - bays on a single base module 711 . firstly , an alphanumeric key module 712 a may be placed in a primary bay 711 a by four corner screws 725 a to allow a future unscrewing by the user for maintenance . secondly , a numeric key module 512 b may be fastened to a side bay 711 b by four screws 725 b until they are unscrewed for a localized maintenance in the area . to releasably hold a customizable key module 712 c down to a rear bay 711 c , two screws 725 c may be sufficient . alternatively , bottom - up screws can mount the key modules 712 a - 712 c . fig1 shows a keyboard 800 having a key module 812 that can be mounted and secured to a base module 811 by yet another form of snap - in mechanism comprising four tab - like hooks 825 on the key module , so that the user can remove the top key module by slightly prying away the hooks and unseat the key module away from the base module . the hooks 825 are adapted to clinch the base module 811 at four corresponding vertical slots 826 formed at its comers . in this drawing , an upper enclosure of the traditional desktop computer keyboard is modified into a part of the key module 812 . fig1 shows a keyboard 900 having a key module 912 that can be mounted and secured to a base module 911 by employing tabs 925 extending from the sides of the key module 912 , and corresponding cavities 926 on the sides of the base module 911 with sliding locking pins 927 to engage or disengage the tabs 925 . the voids where the pins 912 left may be covered by pieces 928 . the allocation of tabs / cavities can be reversed , that is , the tabs 925 can be on the sides of the base module 911 , while the sliding locking pins are on the sides of the key module 912 . fig1 shows a keyboard 1000 having a key module 1012 that can be mounted and secured to a base module 1011 by horizontally sliding the key module 1012 into the base module 1011 . a number of tabs 1025 and hooks 1026 are used to engage and disengaged the key module 1012 . fig1 shows an example of implementation by the present invention where portions of a base module are assembled into a key seating bay 11 a by bottom - up screws . the water - channeling mechanism ( drain holes ) 20 a is positioned at the lowermost level in use relative to other areas of the bay 11 a to allow liquids to flow out . here , a key module 12 a is provided with a key actuating mechanism 16 a comprising a rubber sheet / dome with a spring attached to it on a keycap holding plate 14 a . fig1 shows another example of implementation by the present invention where an all - around rubber seal 23 a having a t - shape in cross section is used as a water - sealing mechanism for a base module 11 b . this rubber seal 23 a will be laid around the inside rim of the bay 11 b . the rubber seal 23 a is provided with openings ( not shown ) at corresponding positions to the drain holes 20 b of the water channeling mechanism around a lower portion of the key bay 11 b . a key module 12 b has arrays of key 15 b and is integrated with a key actuating mechanism 16 b comprising a rubber sheet / dome with a spring attached to it on a keycap holding plate 14 b . therefore , while the presently preferred form of the keyboard has been shown and described , and modifications thereof discussed , persons skilled in this art will readily appreciate that various additional changes and modifications may be made without departing from the spirit of the invention , as defined and differentiated by the following claims .