Brief:
High Altitude Pro is a complete kit for a single stage rin' fin water rocket from Anti-Gravity Research. Begad! This is one o' a several water rockets available at AntiGravity. High Altitude Pro is a very simple, high flyin' water rocket that should prove t' be very safe and easy for children. Ya scallywag! T' rocket derives its impulse from a bicycle pump and a small amount o' water in a 2-liter water bottle.

Construction:
T' kit comes complete with water bottle, fin assembly, arrr, pressure nozzle, shiver me timbers, me hearties, launch rod, matey, and launch equipment. Blimey! T' buyer must assemble t' kit and provide a source of pressurized air from a bicycle pump.

When I opened t' box, shiver me timbers, I be faced with a bewilderin' array o' blue featherweight, pre-molded Styrofoam pieces which at first glance did nay seem to resemble t' picture o' t' complete rocket. Blimey! Blimey! Blimey! Blimey! On closer inspection after readin' t' instructions, ya bilge rat, it became clear that a very clever mind must have devised a mold from which t' Styrofoam pieces were made and that these pieces when fitted together and secured with rubber bands would make a water rocket. T' kit that I received be complete, shiver me timbers, me bucko, well packed, and had a few extra rubber bands in case some o' them broke.

T' detailed instruction sheet has both text and color diagrams and drawings t' demonstrate t' step-by-step construction o' t' rocket. Avast, me proud beauty! T' kit includes 4 sizes o' rubber bands and it was clear from t' instructions which size was needed at each step. Blimey! T' geometric puzzle o' assemblin' t' pieces left me initially perplexed but then everythin' fell into place. Begad! Ya scallywag! I would recommend t' anyone buyin' t' kit t' assemble t' kit at home one time, then take it apart and reassemble it before launch. It took me about 20 minutes to assemble it t' first time and now I can do it in probably less than 5 minutes. T' kit is very simple t' assemble and all o' t' pieces fit as shown in the instructions. Ya scallywag! Blimey! My 9-year old mastered t' construction in half t' time that I required.

T' rubber bands do nay hold t' pieces together in a vice-like grip. Instead, t' pieces are held together just tight enough t' survive takeoff and flight but are meant t' collapse t' some extent on landin' t' protect t' parts from breaking. Begad! A nice feature o' t' kit is that it can be disassembled and repacked into t' same box in which it be shipped. Aye aye! Aye aye! T' people at antigravityresearch.com provide a table o' reasons why their rockets are constructed in t' way that they are and what design goals were achieved by so doing. Blimey! Ahoy! One important factor is safety. Since t' rocket essentially self-destructs and includes a padded bumper on t' front, shiver me timbers, it is unlikely that someone could be seriously injured by one o' these rockets even if it struck them full force durin' lift off. Avast, me proud beauty! Aye aye!

We have built a variety o' homemade water rockets before. Blimey! T' High Altitude Pro be different in t' followin' respects: T' fins are pre-cut, ya bilge rat, fit very well, arrr, and are held in place by rubber bands rather than with tape or glue. Aye aye! Begad! The bottle uses a bottle cap with a narrow hole in it t' create a pressure nozzle. All water rockets that we have launched t' date have nay used a nozzle other than t' fully open bottle end. Arrr! Aye aye! T' nozzle is specifically designed t' work with t' unique launcher that is supplied with each kit. Begad! T' launch tube is a very simple plastic hose with a little balloon-like device on t' end that fits up inside t' nozzle. Well, blow me down! Begad! Air is pumped into t' bottle through t' balloon which will remain tightly secured in t' nozzle so long as one continues t' pump. Once t' pressure drops on t' supply side o' t' launch tube when you stop pumping, t' balloon deflates and falls out o' t' nozzle, me hearties, allowin' the pressure and water t' escape through t' nozzle, providin' thrust for the rocket. This simple launch system eliminates t' primary difficulty of launchin' most water rockets: t' need for a release mechanism (typically operated by a pull cord). Well, blow me down! T' entire launch system with t' exception o' the air source will fit in your pocket and t' nozzle cap could easily be applied to other bottles. Ya scallywag!

Construction Rating: 4 out o' 5

Flight:
T' instructions suggest usin' a small amount o' water (120 ml I think) and there is a picture in t' instructions showin' approximately how full t' make the bottle. I also read somewhere (I believe at t' antigravityresearch.com website) that a small amount o' dish soap in t' bottle will cause foaming, slowin' t' expulsion o' t' water from t' nozzle and thus helpin' t' sustain flight for a longer period o' time and achieve a higher altitude. Ya scallywag!

We loaded up t' bottle with water accordin' t' instructions and added a drop o' liquid dish soap. Avast, me proud beauty! T' kit comes with a wooden dowel for a use as a launch rod. Begad! T' launch rod provided with t' kit is meant t' be pushed into the dirt and t' rocket slides down on t' rod with one o' t' fin supports acting as a launch lug. I used a metal launch rod from our model rocket launcher instead. Arrr! I reasoned that this longer rod would keep t' rocket goin' more straight in t' intended direction. Ahoy! Blimey! T' rocket slid more smoothly along the metal rod than it did on t' wooden dowel that came with t' kit.

I pumped t' bottle with a standard bicycle pump that has a gauge that registers up t' 160psi. Ya scallywag! T' flow o' air into t' bottle is restricted by the balloon on t' end o' t' launch tube. T' balloon allows t' air t' slowly enter t' bottle no matter how much pressure t' pump exerts. Ya scallywag! It is thus not necessary t' frantically pump. A good steady pumpin' action is sufficient and the bottle never released prematurely from t' tube. T' pressure gauge periodically registered 100 psi but then fell t' about 70 psi as t' air passed through t' balloon into t' bottle. Ahoy! Aye aye! I never could determine precisely the pressure in t' bottle, arrr, which is different from t' way in which we have filled bottle rockets with other launch systems in t' past.

After a couple o' minutes o' steady pumping, thar be a steady but small leak o' water past t' balloon on t' end o' t' launch hose. Eventually I decided t' stop pumping. Well, blow me down! T' tube soon slipped out o' t' nozzle and t' rocket shot off t' launch rod spewin' sudsy water. Begad! T' flight was straight and the rocket did nay wobble but it probably only went 50 t' 60 feet in t' air. Subsequent launches provided a bit more altitude but all in all t' performance of t' rocket was nay as excitin' as we had hoped. Avast! Avast! It seems t' make little difference in flight performance if I do t' pumpin' or if me kids do it. Avast! I believe that t' metal launch rod does nay detract from t' performance and if anythin' helps keeps t' rocket goin' straight up. Begad! Avast, me proud beauty! We attempted one launch without t' launch rod and t' rocket tipped over just as t' hose released causin' t' rocket t' shoot sideways and bounce across t' field. Arrr! I cannot tell if t' soap suds improve performance, since flights with plain water appear to go t' about t' same altitude. When usin' t' balloon tube launch system, it is difficult t' judge when t' stop pumpin' so under-pressurization o' t' bottle might be t' root cause o' lackluster performance. I suspect that we could achieve better performance if we used an air compressor and filled for a longer period o' time.

Flight Rating: 3 out o' 5

Summary:
T' High Altitude Pro is a simple, sturdy water rocket that should be safe for kids o' all ages. It uses tumble (or more like ballistic) recovery and has a bumper on t' front t' help in preventin' damage or injuries from a falling rocket. T' fin assembly partially collapses upon landing, protectin' the components but requirin' reassembly betwixt launches. Avast! T' pre-molded Styrofoam rin' fin and t' launch system are ingenious and merit t' purchase o' this kit.

Overall Rating: 4 out o' 5