/// api_version=2
var script = registerScript({
    name: "AAC5BoatFly",
    version: "1.00",
    authors: ["ys_"]
});
var blink = moduleManager.getModule("Blink");
var delay = 0;
var state = 0;
script.registerModule({
    name: "AAC5BoatFly",
    description: "Fly in aac5 with boat",
    category: "Movement",
    settings: {
        EditSpeed: Setting.float({
            name: "EditSpeed",
            default: 1.0,
            min: 0.0,
            max: 1.5
        }),
        YMotion: Setting.float({
            name: "YMotion",
            default: 0.0,
            min: -0.5,
            max: 0.8
        }),
        Delay: Setting.integer({
            name: "KeepTime",
            default: 10,
            min: 0,
            max: 30
        })
    }
}, function (module) {
    module.on("enable", function () {
        delay = 0;
        state = 0;
    });
    module.on("update", function () {
        delay++;
        if (module.settings.Mode.get() == "Riding") {
            if (mc.thePlayer.isRiding()) {
                state = 1;
                delay = 0;
            } else if (state >= 1) {  // was riding
                blink.getValue("Pulse").set(false);
                blink.setState(true);
                delay = 0;
                if (mc.thePlayer.onGround) {
                    mc.thePlayer.capabilities.isFlying = true;
                    state++;
                    mc.thePlayer.motionY = module.settings.YMotion.get() + 0.42;
                    setSpeed(0);
                }
                if (module.settings.Delay.get() > delay) {
                    mc.thePlayer.capabilities.isFlying = true;
                    addSpeed(Math.min(module.settings.EditSpeed.get() / 10, 0.5) + 0.3);
                    mc.thePlayer.motionY = Math.max(mc.thePlayer.motionY, 0);
                }
            }
        }
    });
    module.on("disable", function () {
        mc.thePlayer.capabilities.isFlying = false;
        blink.setState(false);
    });
});


function setSpeed(_speed) {
    var playerYaw = radians(mc.thePlayer.rotationYaw);
    mc.thePlayer.motionX = _speed * -Math.sin(playerYaw);
    mc.thePlayer.motionZ = _speed * Math.cos(playerYaw);
}

function addSpeed(_speed) {
    var playerYaw = radians(mc.thePlayer.rotationYaw);
    mc.thePlayer.motionX += _speed * -Math.sin(playerYaw);
    mc.thePlayer.motionZ += _speed * Math.cos(playerYaw);
}

这一串是我从我自己的另一个js上扣下来的片段，也许有些不太完整，如果不能用记得告诉我，
希望能对大家有所帮助

或者根据这个流程自己改：

坐船
下船 开Blink
脚着地 设置动量 让玩家处于飞行状态
加速度直到时间超过delay设置

完事之后:
让玩家不处于飞行状态
关掉Blink

注意事项:
完事之后不能直接reset motion，不然有你好受(雾)，要减速的话motionXZ *= 0.6就差不多了

（原理来自yt，详细流程和代码来自我自己，抄可以抄，标上出处即可）