If you want a Seaplane and your budget is tight maybe one of these Flying boats might suit you well. Not sure how much commercial success any of the following designs has received but they sure do look fun.
Don’t expect to cruise fast, cruise speed for these craft is around 40 knots with stall speed around 25 knots. There is a fair amount of drag created by the hull.
Ramphos Flying boat
The Ramphos flying boat from the Philippines looks to be the most widely sold and structurally strong model. The wing is made of aircraft grade stainless steel and the hull is made of composite vacuum epoxy resin and is enforced by kevlar and carbon.
There are engine options available, the Rotax 503, Rotax 582 (two stroke) and the Rotax 912 (four stroke). With these engines the craft can get off the water in 7-10 seconds or less than 80 meters. Empty weight for the Hydro version without landing gear is 198 kg. For the amphibian model with extendable landing gear the weight is 225 kg.
Gross weight is 450 kg so there is a useful load of around 250 kg, depending on the model. This boat sits a lot lower in the water than the inflatable models on the list so you would want to make sure the water is calm. The selling price for the machine is €22,500.
Polaris AM-FIB Flying boat
The Polaris AM-FIB is an Italian produced flying boat. The wing is made of aluminium tubing covered by Dacron sailcloth. It is powered by a twin cylinder, liquid-cooled, two-stroke, dual-ignition 64 hp (48 kW) Rotax 582 engine.
The hull is an inflatable outer tube with rigid fibreglass hull. Empty weight for the machine is 239 kg and maximum take-off weight is 406 kg. The machine has gear that are retractable via a lever. While not the most aerodynamic on the list it definitely would fair the best in rougher water.
Currently the website for the Polaris is down so it is impossible to get the latest information on prices or availability.
Seair Flying boat
The Seair is a US designed flying boat. The wing is a 19 meter Northwing Mustang Trike wing constructed of Aluminium tubing. The hull is made of 5052 Marine Grade Alloy, with 6061 T-6 Aluminum structural supports and has an inflatable outer tube with triple Chamber floats, constructed from high quality Neoprene.
Empty weight for the craft is around 200 kg with a maximum take-off weight of weight of 450 kg. The selling price on the website is $21,000 USD. They generally manufacture the boats in lots of 10 so there can be a waiting time to get your machine.