The third installment in the assault boat line boasting a bigger payload with this variant sporting a twin 37mm guns with 4 allied captured hmg guns for antiair. The its 7 torpedos for long range ship combat and twin fixed 75mm naval guns to do close ship to ship combat.the cockpit though looks small but is quite roomy compared to the other ships in the line ( except the 488 variant) due to the problems with the other assault boats were the cockpit was to easy pick off in ship to ship combat so the navy decided to make the cockpit a sidesaddle. The purpose of the AB line was to replace pt boats in 1947 while the germans were devloping the s boot ( a overhauled R boot with very deadly upgrades) since the germans and japanese jumpstarted the korean war by supplying the koreans with adis technology