Hi, I'm very new to 3D printing but yet very fascinated about it. The S.T.E.A.M make it float challenge is interesting and challenging so I’ll try to design a boat that can carry as much weight as possible in comparison to its own weight. All in all I created 4 designs to be able to exploit all different physical phenomena of the buoyancy. 1.Forceamaran: Body: I started with a really simple structure to be able to test, how much a simple 3D print is able to carry. On the bottom the triangular shape centers the weight. On the top are small arms to get more stability. Frist test: 3D printed weight: 14g. Weight of the coins it carried: 39g --> boat can carry roughly 2.8 times It’s own weight. Next Step: Mimic a trimaran. I designed 2 support boats for both sides which in principal is a copy of a trimaran. The difference is, that the support boats have a tilted bottom. If you know apply weight to the supports, they will tilt to the side and apply a force to the middle boat (body) which should improve the weight the body can carry. Result: the force of the support boats applied on the body is so little that it does not improve the weight the body can carry significantly :( The weight of the forcamaran (2xsupport + body) was 45g and it has been able to carry 56g of coins --> it carries 1,24 its own weight which is much worse than just the body. But at least it is much more stable with the supports ;) 2.Floating Island: This design uses the buoyant force resulting from the pressure difference of differently steep water. It consists of a cube and a stick on the top. The cube is 5x5x2 cm and the stick 10 cm. Let’s do a bit of calculation: Force = Pressure [Pa = N/m²] Surface [m²]. On the bottom plane of the cube appeals a force of 1200 N/m² 1/400 m² = 3N. On the top of the top plane of the cube appeals a force of 1000 N/m² 1/400 m² = 2,5N. The buoyancy is the difference of the two forces which is 0.5N. As the weight force G = m g (Gravitation force) one can calculate that this construction will be able to carry ~ 50g. This has been experimentally approved as can be seen by the pictures ;) Result: The Islands weight is 18g. It has been able to carry 45g --> The island carries exactly 2.5 times its own weight, which is not as good as the forcamaran body has been able to carry. Additionally the Island is extremely unstable which made it hard to apply any weight. Improvement: As the above formula for the Force suggests, the bottom surface of the cube should be as big as possible and the top plane as small as possible. Additionally the bottom and top plane should be as far apart as possible to achieve a big pressure difference. The infill of the cube should be as light as possible. Air is good, helium would be better. I designed a new floating Island but did not print it yet. On the bottom of this new design appeals a force of 2900 N/m² 1/100 = 29N. On the top of the cube appeals a force of 2000 N/m² 1/10000 = 1/5 N. The difference of both forces is 28,8 N --> the design should be able to carry ~ 3kg. 3.Funnel: This design uses the buoyant force resulting out of the Archimedes' principle. The more fluid one is able to displace the higher the buoyant force. So I created a really simple 3D design which has the same structure as a funnel just in cubic shape, because it’s easier to print. Reuslt: The funnels weight is 17g and it has been able to carry 368g! --> The funnel has been able to carry ~21.6 times its own weight! This is by far the best I have been able to achieve. Improvements: I chose an angle of 45° (1cm in z direction for every cm in x or y direction). A smaller angle could lead to even better results as more water is displaced with the same amount of material. 4.Hovercraft: Last but not least I wanted to create a good looking design which is able to float. As I’m a huge fan of Hovercrafts, I tried to mimic the design of a hovercraft. If I got time, I will design a fan that will be able to blow air in the chambers to make it levitate above the ground and an engine to power the fan on the back. Thanks for reading through till here. Greetings ;) Body: print upside down! resolution: printed 0.3 mm layer height --> got a few cracks. Should be printed with 0.2 mm. Speed: 70 mm/s works fine.