fig1 a shows a front perspective view of the lower half tower 10 as it would appear on a boat . the bottom tower structure 10 is directly mounted onto deck section and gunwales of a boat . in most desired configurations , the tower platform would cover the helm , control console , and portion of the cockpit area of the vessel . as shown , the bottom tower structure 10 is comprised of a pair of support ladders 12 located at the aft section of the lower half tower 10 . the ladders 12 are mounted to the boat in a conventional manner , using appropriate pads , flanged ends , or mounting plates 14 . the fore or bow side of the half tower 10 comprises a plurality of leg members 16 , also having flanged ends or mounting plates 17 . as shown in one embodiment , there are a pair of fore leg members 16 , each having three ( 3 ) discrete leg elements . it is contemplated , however , that a greater or lesser number of leg elements could be utilized , depending on design choices and vessel configurations , as the instant invention is applicable of a variety of boat and yachts . these include , for example , express cruisers , sport yachts , fly bridge , sedan cruisers and the like . the precise number of leg elements utilized depends on shape and configuration of the boat hull , cockpit and helm area , cabin roof and decks . it is contemplated that each leg frame member 16 and the leg elements will be mounted to a different location on a boat , so as to provide further stability for the half tower 10 . as shown , a first half tower platform 18 is securely mounted to , and supported by , the ladders 12 and leg members 16 at opposite ends from the mounting plates 14 , 17 . as discussed above , the hard top platform 18 can incorporate a one piece fiberglass core , or two piece fiberglass layers over rectangular or tubular aluminum members . the platform 18 is structurally sound so as to support boat occupants , communication , navigation and / or fishing equipment . as would be apparent to one of ordinary skill in the art , other rigid platform could be utilized in the instant invention . in alternative embodiments , first elevated deck or platform 18 is supported by , and secured to , a generally horizontal metal framework , which constitutes a separate tubular or rectangular metal frame corresponding generally to the shape of the platform and inset from its periphery . the ladders and legs are secured to the horizontal framework in conventional means , including welding , using hardware , or bonding techniques . in alternative embodiments , the platform can include integral reinforcement members within the molded fiberglass top , such as metal plates or flanges , internal tubular or rectangular metal braces , or the like . the half tower legs or ladders are then secured directly to the hard top . at the location where the ladders 12 mount to the first platform 18 , there are cut - out sections 19 in the platform which can provide generally semi - circular insets or voids in the corner areas of the hard top to allow a person climbing the ladder to upper levels to pass through or around the platform unobstructed . the platforms can also contain further voids , windows or holes in other areas , such as its center , for mounting satellite or radar units , accessory electronics or hardware , or the like . the cut - outs 19 have a size and shape to allow a person to comfortably fit through . as shown , a variety of devices may be mounted onto the top of the first platform 18 . for example , a radar antenna can be mounted onto the first platform 18 . it is contemplated that the first platform 18 is equipped with recessed areas to receive fixtures for navigational lights , cockpit lights , or electronic devices along the edges of the platform , as well as internal channels for routing necessary electrical wiring , cabling , hydraulic or pneumatic lines , or similar hardware . additionally , it is contemplated that the ladders 12 and the leg members 16 may be hollow and tubular , with internal channels , so as to allow for routing the necessary wiring or cables . fig1 b illustrates a front perspective view of a top tower section 20 of the instant invention . the top tower structure 20 is specially designed with custom components and functional ability , such that the entire unit can be directly mounted onto the original half tower 10 of a vessel . it is to be appreciated that the original boat was either purchased with the half tower in original manufacturing as oem equipment , or the half tower of the instant invention was added to the boat later . in either event , once the boat owner desires to upgrade the vessel and tower , and install a complete , full tower with multiple elevated platforms , the instant invention accomplishes that goal . second upper tower section 20 fulfills this need , and “ converts ” the original half tower to a full tuna tower or alternative full tower design . this is accomplished by the complementary and interfacing design features of upper tower section 20 , and the specially designed mating hardware components of the separate sections . upper tower section 20 is placed over and secured to first platform 18 of the bottom tower structure 10 utilizing ladders 22 and leg members 27 . the ladders 22 and leg members 27 are mounted to the bottom tower structure 10 through the use of mounting pads 24 on the base of the ladders 22 and mounting pads 26 on the base of the leg members 27 . the mounting pads 24 , 26 allow the ladders 24 and leg members 27 to be quickly and easily mounted to the bottom tower structure 10 . the mounting pads 24 , 26 may have any shape necessary to maximize effectiveness , however a key aspect of this invention is that the mounting flanges , plates , pads and bolting hardware are precisely aligned and mated with corresponding structure of the lower half tower 10 . thus , the lower termination points of the ladders 22 and support legs 27 of upper tower section 20 , are aligned with structurally reinforced areas of the lower tower platform 18 , ladders 12 and support legs 16 of lower half tower 10 . all ladders can be coaxially aligned , and certain leg elements can also be coaxially aligned . ladders 22 are further aligned directly over the cut - outs 19 in the first platform 18 so to accomplish the above , and to allow a user to climb up the ladders 12 on the bottom tower structure 10 , through the cut - outs 19 , and continue climbing up the ladders 22 on the top tower structure 20 . it is contemplated that additional bracing mechanisms 23 , 25 may be utilized between the leg frames 27 and the ladders 22 to add structural rigidity to the upper tower structure 20 . it is further contemplated that a second platform 28 will be mounted between the leg frames 27 and the ladders 22 . as shown , the rungs of the ladders 22 on the upper tower structure 20 cease at the level where the second platform 28 is mounted . thus , the user can climb up the ladders 22 and step onto the second support platform 28 , which acts as an elevated hard top and floor or standing platform for the uppermost redundant drive station 30 . it is further contemplated that a drive console 30 may be mounted near the top of the ladders 22 and the leg frames 27 , and if desired additional aluminum or metal tubing can act as framework . the drive console 30 will further have a sun or equipment cover 32 , to protect the user from the elements . the additional cover 32 can be a fabric bimini top , or alternative hard top , and either type can be reinforced to mount accessory equipment on the top thereof as shown in fig1 b . second platform 28 also may be equipped with recessed fixtures for leds along the edges as well as internal channels for routing the necessary electrical wiring . additionally , it is contemplated that the ladders 22 and the leg frames 27 may be hollow and tubular so as to allow for routing the necessary electrical wiring or cables . such electrical wiring , hydraulic or other cabling will extend to the drive station and console 30 to allow a captain to operate the boat and navigate from the uppermost elevated station . optional conventional equipment includes seating , steering wheels , throttles and an instrument panel . fig1 c depicts a front perspective view of the completed conversion to full tower 40 , with the upper tower section 20 mounted onto lower half tower 10 through the use of mounting plates 26 , 24 . it will be appreciated that alternative mounting components and techniques can be utilized , including interlocking arms , recessed receivers , and welding . fig2 a shows a rear perspective view of the bottom tower structure 10 as it would appear on a boat . fig2 a provides a further representation of the location and shape of the cut - outs 19 located on the first platform 18 . fig2 b shows a rear perspective view of the top tower structure 20 as it would appear on a boat . fig2 c shows a rear perspective view of the complete conversion to full tower 40 with the top tower structure 20 mounted onto the bottom tower structure 10 . fig3 a illustrates a right side plan view of the bottom tower structure 10 as it would appear on a boat . fig3 a provides a further representation of the shape and length of the ladders 12 and leg members 16 . fig3 b shows a right side plan view of the top tower section 20 as it would appear on a boat . fig3 c shows a right side plan view of the completed conversion to full tower 40 with the top tower structure 20 mounted onto the bottom tower structure 10 . fig4 a depicts a front plan view of the half tower 10 as it would appear on a boat . fig4 b shows a front plan view of the upper tower section 20 as it would appear on a boat . fig4 c shows a front plan view of the completed conversion to full tower 40 . fig5 depicts a top plan view of full tower 40 . fig6 illustrates a perspective view of a section of the boat hardtop 50 of the instant invention , with a recessed light fixture 52 within the hardtop , a radar unit 54 , and antennas 56 mounted on hardtop 50 . fig7 a shows an enlarged section of the recessed light fixture 52 installed within hardtop 50 of fig6 . fig7 b shows a sectional top plan view of the light fixture 52 installed within the hardtop 50 . the light fixture includes an electronic module and leds 54 as well as lens 56 . electrical wires and conductive lines 58 are shown within the hardtop 50 . fig7 c shows an enlarged section of the recessed light fixture 52 and hardtop 50 of fig6 , as the light fixture 52 is inserted within the hardtop recess 60 . the electronic module 54 and lens 56 are also illustrated . fig8 shows a reinforcing plate 62 installed within a section of the boat hardtop and the mounting area 64 of the hardtop which receives a leg flange as discussed above . the reinforcing plates can be of any thickness required as known to one of ordinary skill in the art , and is integrally formed within the fiberglass top during the manufacturing process utilizing known techniques for molds , laminates , fiberglass formation , pouring composites and thermoplastics , shaping and the like . the plates can be made from materials such as steel , structural aluminum or composites as a matter of design choice . fig9 shows top plan view of the hardtop 501 with internal channels 66 for receiving and housing internal electrical wiring , cabling for steering systems , communication lines , coaxial cables and the like . also shown are integral reinforcing circular plates 68 which are coaxially aligned to support the leg members of conversion tower units . with respect to fig1 a , this view illustrates a rear perspective view of a complete conversion tower incorporating the instant invention . fig1 b and 10 c , depict the enlarged perspective view of the left and right rear ladders and platform sections , and the mounting assembly there between . lower ladder leg members 90 and 92 are coaxially aligned and structurally secured to upper leg members 94 and 96 . reinforcing plates 98 are integral components of the hard top - platform assembly , and provide the structural reinforcement and support for the upper ladders , upper legs and upper tower assembly . fig1 d illustrates an enlarged perspective view of the front right leg member and the front right platform section of the completed tower assembly . upper leg member 102 and lower leg member 104 meet in coaxial alignment with structural reinforcing plate 106 interposed therein . also shown is an addition light fixture 108 and internal channel 110 . fig1 e shows light fixture 98 mounted within the central core of the platform and into the receiving channel 100 . in reference to fig1 a , the hard top 70 is generally depicted in an exploded perspective view . hard top 70 is generally comprised of a three part platform in this embodiment , constituting the underside fiberglass surface or skin 72 , the central core 74 , and the upper most top surface or skin 76 . these surfaces can be fiberglass or alternatively other composites or materials in specific embodiments . the central core 74 of the platform / hard top includes internal channels 78 which , as referenced above , are utilized for the running of conduits , electrical wiring , hydraulic lines and the like . fig1 b illustrates an enlarged perspective view of the front right section of the internal and central core of the platform . an electrical lighting fixture 80 is depicted for insertion into the central core 74 , in a manner as described with respect to fig7 a through 7 c above . also shown is reinforcing plate 82 , which can be selected from metal plates , pads , flanges , or internal braces as discussed above . reinforcing plates or pads 82 , depicted in both fig1 b and 11 c , provide the structurally supporting interface between the front leg members of the lower tower units and upper tower units which are mounted to the hard top and platform assemblies . fig1 d illustrates a perspective view of the central core 74 of the platform , which comprises the center of the hard top . also shown are the internal channels 78 to accommodate various electrical and / or mechanical equipment . fig1 e illustrates an enlarged perspective view of the left rear ladder and reinforcement section of the central platform core for the conversion tower . reinforcing plates 84 accommodate the ladder pads , flanged ends , or mounting plates located at the ends of the ladder legs , as illustrated in fig1 a and 1 b . the reinforcing plates again provide the structural interface and support within the hard top 70 , and allow the lower ladder sections and the upper ladder sections to be structurally secured to one another in a correct and predetermined coaxial alignment . fig1 f illustrates the lighting fixture 80 for insertion into the rear center light section of the central core platform , and into the receiving channel . fig1 illustrates a cross sectional view of the mounting and manufacturing assembly which secure the leg members of the lower tower sections to the leg members of the upper tower sections . this includes the ladder legs as well as the separate legs . lower tower tube or pipe 110 includes mounting flange or base 112 . upper tower tube or pipe 114 includes mounting flange or base 116 . the mounting flange or base of upper leg member 114 and lower leg member 110 are secured to one another utilizing hardware 118 . as will be apparent to one of ordinary skill in the art , alternative mounting hardware can be incorporated into the instant invention , such as threaded bolts , nuts , welded rods or any other equivalent structure . the terminating ends of upper tower leg member 114 and lower tower leg member 110 can include appropriate mounting pads or shaped flanges 120 . the mounting pads or bases can be secured to the respective leg members utilizing appropriate welds , bonds , or alternatively can be manufactured as integral components and terminating in flanged ends of the leg members . this would be accomplished through appropriate designs for tooling and molds used in manufacturing the tubular leg members . the hard top is depicted , which includes the top fiberglass surface or skin 122 , the bottom fiberglass surface or skin 124 , and the central core platform 126 of the instant invention . in a particular embodiment , the core platform is manufactured from an appropriate foam composition as well known in the manufacturing industry . alternative foams are available of different densities and chemical compositions , including appropriate structural foams where desired . the central core could also be solid fiberglass if desired , or certain sections thereof . also indicated is an example of a reinforcing mounting plate 130 , which provides the structural support and interface between the lower leg member 110 and upper leg member 114 . the reinforcing plate 130 would be manufactured from an appropriate structural material , including various metal compositions , steel , alloys and the like . the platform &# 39 ; s integral reinforcing member 130 is positioned between the mounting pads , flange or base 120 of the upper and lower leg members , all coaxially aligned with one another , and generally centered with respect thereto . in alternative embodiments , reinforcing members 130 can be of any particular geometric shape , the important element being to provide the structural support and / or internal brace to provide a secure foundation between the leg members of the lower tower unit and the upper tower unit , whether the leg members are individual members , or paired leg members of any desired ladder . the instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment . it is recognized , however , that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art .