referring to fig1 and fig2 , floating lift 100 comprises a watercraft lift apparatus 102 affixed to a buoyant support frame 104 . in the depicted embodiment , the support frame 104 includes two adjustable transverse beams 106 , 108 that are attached to lift 102 by connectors 110 located on each end 112 of parallel longitudinal beams 114 a , 114 b on lift 102 . attachment to connectors 110 may be accomplished by welding , fasteners , or other known methods . transverse beams 106 , 108 are formed of tubular metal having a substantially square cross - sectional shape that defines a hollow longitudinal interior 116 that opens at each end 118 . lift 102 holds transverse beams 106 , 108 in spaced parallel relationship . in use , the floating lift 100 is positioned in a body of water with the support frame 104 attached to the floor of the body of water . the support frame stands upon support stands 120 , resting upon base plates 122 , suitably secured in a conventional manner that will not be described in detail herein . stands 120 connect to catwalks 124 via arcuate bands 126 , which encompass inflatable pontoons 128 . pontoons 128 may be inflated with air or other gas to provide buoyancy . in the depicted embodiment , catwalks 124 rest upon floating inflatable pontoons 128 and thereby support buoyant support frame 104 . while the preferred embodiment is depicted , other arrangements for the inflatable pontoons 128 to provide buoyancy to frame 104 are within the scope of the present invention . for example , both the catwalks 124 and the pontoons 128 may be directly connected to frame 104 . in this embodiment , stands 120 are laterally positioned by sliding the lateral beams 130 with respect to front and rear transverse beams 106 , 108 and affixing them with suitable fasteners . once base plates 122 are anchored , buoyant support frame 104 is adjusted vertically along adjustment post 129 , thus keeping lift 102 at the right height with respect to the surface of the water . as depicted , pontoons 128 are each comprised of pairs of tubes of polymer coated fabric material , made airtight and fitted with valves for inflation and deflation in the manner of inflatable rafts of rubberized fabric , well known to those in the art . as will be appreciated by those of skill in the art , a wide variety of other configurations of inflatable pontoons are possible in keeping with the teachings of the present invention . it is preferred that each pontoon 128 comprise a plurality of inflatable members , so that in the event of a rupture , the pontoon will still retain partial buoyancy . as will be further appreciated by those of skill in the art , other embodiments of the present invention are possible wherein inflatable pontoons are fabricated of materials other than polymer coated fabric , such as sheet elastomer or heavy gauge sheet mylar ®. it is to be understood that pontoons comprised of any material are within the scope of the present invention , so long as such pontoons may be inflated with air for flotation and are substantially reduced in volume when deflated . in the presently depicted embodiment , pontoons 128 are secured to catwalks 124 by nautical ropes 130 which are threaded through handles 132 that are affixed to pontoons 128 . the depicted handles 132 are comprised of a rigid material , such as solid polymer , affixed to pontoon 128 by bonding to a rigid or semi - rigid reinforcing sole within pontoon 128 , and made airtight with pontoon 128 by polymeric seal with the material comprising pontoon 114 , in a manner well - known to those in the art . as will be appreciated by those of skill in the art , various other conventional means may be employed to secure inflatable pontoons 128 to catwalks 124 . by way of example , such means may include nylon straps instead of nautical ropes . by way of further example , pontoon 128 may be secured to catwalk 124 by a connecting means such as a clamp attached to catwalk 124 which directly engages an attachment such as handles 132 in the pontoon 128 . by way of yet further example , catwalk 124 may be integral to pontoon 128 , comprising a rigid or semi - rigid element disposed within and / or bonded to the polymer coated fabric or other material comprising pontoon 128 . watercraft lift apparatus 102 may be of any design whose dimensions and extensions in operation are accommodated by buoyant support frame 104 . an exemplary lift apparatus is that described in u . s . pat . no . 5 , 184 , 914 , issued to the inventor of the present invention and incorporated herein by reference . in the depicted embodiment , lift 102 comprises a base made up of front and rear beams 134 , 136 and transverse beams 114 a , 114 b . two pair of upwardly extending booms 138 , 140 are each pivotally connected at their lower end to the base at its corners . the members of each pair of booms are rigidly connected to each other in parallel by cross supports 142 , 144 . two substantially horizontal arms 146 are each pivotally connected to one member of each pair of booms 138 , 140 at the upper end of the boom , so that each arm pivotally connects to one member of one pair of booms 138 at one end of the arm and to one member of the other pair of booms 140 at the other end of the arm . two connected , collapsible parallelograms are thereby formed , one on each side of the base formed by 114 a , 114 b , 134 and 136 , the corners of each parallelogram comprising the upper and lower pivot points of the front and rear booms 138 , 140 on one side of the base . the pivotally connected arms lie in a plane , which is lowered as the parallelograms are collapsed and is raised when the parallelograms are expanded . a watercraft supported by support means connected to the arms in that plane may thereby be lowered and raised as the parallelograms are respectively collapsed and expanded . an expanding and contracting actuator , 146 , such as a hydraulic cylinder , supplies the motive force for expanding the parallelogram for lifting watercraft . in preferred embodiments of watercraft lifts , such as claimed in &# 39 ; 914 , the parallelogram expands over - center , so that initially obtuse angles of the parallelogram become acute and initially acute angles become obtuse , providing an advantageous , gravity - based locking for raised lifts . such a lift requires that the actuator be double - acting , providing expanding actuation for raising , but also providing contracting actuation for moving the lift back over center for lowering , as provided preferably by a double - acting hydraulic cylinder . as will be appreciated by those of skill in the art , however , the present invention will accommodate a wide range of embodiments of watercraft lift 102 , not limited to those expressly described herein . accordingly , it can be seen that the invention described herein provides an improved floating watercraft lift apparatus wherein the buoyancy of the lift is supplied by inflatable pontoons . because the pontoons are inflatable and deflatable , the pontoons may be shipped deflated to the boat lift location and , in situ , both inflated for deployment and deflated for maintenance or relocation . although the detailed descriptions above contain many specifics , these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention . various other embodiments and ramifications are possible within its scope , a number of which are discussed in general terms above . while the invention has been described with a certain degree of particularity , it should be recognized that elements thereof may be altered by persons skilled in the art without departing from the spirit and scope of the invention . accordingly , the present invention is not intended to be limited to the specific forms set forth herein , but on the contrary , it is intended to cover such alternatives , modifications and equivalents as can be reasonably included within the scope of the invention . the invention is limited only by the following claims and their equivalents .