An inflatable slide comprising: an elongated member comprising a sliding surface; and a support structure supporting the elongated member, the support structure comprising a first rail beam and a second rail beam bordering opposites sides of the elongated member, wherein the first rail beam and the second rail beam are inflatable, wherein the first rail beam and the second rail beam each have a four-point cross section, wherein the four-point cross section is defined by a first pair of opposing arcuate sections comprising a first inflatable arcuate section having a first peak point and a second inflatable arcuate section having a second peak point said first and second peak points defining a first large transverse dimension, and a transverse pair of opposite arcuate sections comprising a third inflatable arcuate section having a third peak point and a fourth inflatable arcuate section having a fourth peak point said third and fourth peak points defining a second large transverse dimension, wherein said first large transverse dimension between the first peak point and the second peak point intersects said second large transverse dimension between the third peak point and the fourth peak point, and wherein the four-point cross section is further defined by a first indent formed between the first arcuate section and the fourth arcuate section, a second indent formed between the second arcuate section and the third arcuate section, a third indent formed between the third arcuate section and the first arcuate section, and a fourth indent formed between the second arcuate section and the fourth arcuate section, and wherein the four-point cross section of each of the first and second beams is made from three or fewer chambers. an elongated member comprising a sliding surface; and a support structure supporting the elongated member, the support structure comprising a first rail beam and a second rail beam bordering opposites sides of the elongated member, wherein the first rail beam and the second rail beam are inflatable, wherein the first rail beam and the second rail beam each have a four-point cross section, wherein the four-point cross section is defined by a first pair of opposing arcuate sections comprising a first inflatable arcuate section having a first peak point and a second inflatable arcuate section having a second peak point said first and second peak points defining a first large transverse dimension, and a transverse pair of opposite arcuate sections comprising a third inflatable arcuate section having a third peak point and a fourth inflatable arcuate section having a fourth peak point said third and fourth peak points defining a second large transverse dimension, wherein said first large transverse dimension between the first peak point and the second peak point intersects said second large transverse dimension between the third peak point and the fourth peak point, and wherein the four-point cross section is further defined by a first indent formed between the first arcuate section and the fourth arcuate section, a second indent formed between the second arcuate section and the third arcuate section, a third indent formed between the third arcuate section and the first arcuate section, and a fourth indent formed between the second arcuate section and the fourth arcuate section, and wherein the four-point cross section of each of the first and second beams is made from three or fewer chambers. wherein the first rail beam and the second rail beam are inflatable, wherein the first rail beam and the second rail beam each have a four-point cross section, wherein the four-point cross section is defined by a first pair of opposing arcuate sections comprising a first inflatable arcuate section having a first peak point and a second inflatable arcuate section having a second peak point said first and second peak points defining a first large transverse dimension, and a transverse pair of opposite arcuate sections comprising a third inflatable arcuate section having a third peak point and a fourth inflatable arcuate section having a fourth peak point said third and fourth peak points defining a second large transverse dimension, wherein said first large transverse dimension between the first peak point and the second peak point intersects said second large transverse dimension between the third peak point and the fourth peak point, and wherein the four-point cross section is further defined by a first indent formed between the first arcuate section and the fourth arcuate section, a second indent formed between the second arcuate section and the third arcuate section, a third indent formed between the third arcuate section and the first arcuate section, and a fourth indent formed between the second arcuate section and the fourth arcuate section, and wherein the four-point cross section of each of the first and second beams is made from three or fewer chambers.