Please help need quick!!! Thanks

hey i keep getting stupid compile errors and don't understand why. i'm supposed to use abstract to test a boat race simulation program of sorts here is my code:

RentforthBoatRace.java

public abstract class RentforthBoatRace {

    public abstract double getSum();


}

testRentforthBoatRace.java

import java.util.Scanner;

public class TestRenforthBoatRace {

    public static void main(String args[]) {

    double lowest = getLowestWeight();

        RedBoat redboat = new RedBoat(makeTeam());
        GreenBoat greenboat = new GreenBoat(makeTeam());
        YellowBoat yellowboat = new YellowBoat(makeTeam());
        BlueBoat blueboat = new BlueBoat(makeTeam());
        OrangeBoat orangeboat = new OrangeBoat(makeTeam());

    System.out.println("The winner is " + lowest);

}
    public static double[] makeTeam(){

        Scanner input = new Scanner(System.in);

        double[] team = new double[10];

        for(int i = 0; i < team.length; i++){
            team[i] = input.nextDouble();
        }

        return team;
}

    public static double getLowestWeight(double[] array) {  

        double lowest;

            array[0] = redboat.getSum();
            array[1] = greenboat.getSum();
            array[2] = yellowboat.getSum();
            array[3] = blueboat.getSum();
            array[4] = orangeboat.getSum();

            for(int i = 1; i < array.length ; i++){  
                if(array[i] < lowest){  

                    lowest = array[i]; 
                }
            }
            return lowest;
    }


}

RedBoat.java

public class RedBoat extends RentforthBoatRace {

private double[] team1 = new double[10];

public RedBoat( double[] team1){

    for(int i = 0; i < team1.length; i++) {
        this.team1[i] = team1[i];
    }

}

public double getSum(){
    double sum = 0;

    for(int i = 0; i < team1.length; i++){
        sum = sum + team1[i];
    }

    return sum;

}
}

GreenBoat.java

public class GreenBoat extends RentforthBoatRace {

private double[] team1 = new double[10];

public GreenBoat( double[] team1){

    for(int i = 0; i < team1.length; i++) {
        this.team1[i] = team1[i];
    }

}

public double getSum(){
    double sum = 0;

    for(int i = 0; i < team1.length; i++){
        sum = sum + team1[i];
    }

    return sum;

}
}

YellowBoat.java

public class YellowBoat extends RentforthBoatRace {

private double[] team1 = new double[10];

    public YellowBoat( double[] team1){

    for(int i = 0; i < team1.length; i++) {
        this.team1[i] = team1[i];
    }

}

public double getSum(){

    double sum = 0;

    for(int i = 0; i < team1.length; i++){
        sum = sum + team1[i];
    }

    return sum;

}
}

BlueBoat.java

public class BlueBoat extends RentforthBoatRace {

double totalWeight4;

private double[] team1 = new double[10];

    public BlueBoat( double[] team1){

    for(int i = 0; i < team1.length; i++) {
        this.team1[i] = team1[i];
    }

}

public double getSum(){
    double sum = 0;

    for(int i = 0; i < team1.length; i++){
        sum = sum + team1[i];
    }

    return sum;

}
}

OrangeBoat.java

public class OrangeBoat extends RentforthBoatRace {

double[] team1 = new double[10];

    public OrangeBoat( double[] team1){

    for(int i = 0; i < team1.length; i++) {
        this.team1[i] = team1[i];
    }

}

public double getSum(){
    double sum = 0;

    for(int i = 0; i < team1.length; i++){
        sum = sum + team1[i];
    }

    return sum;

    }
}

compile errors:

TestRenforthBoatRace.java:7: getLowestWeight(double[]) in TestRenforthBoatRace cannot be applied to ()
    double lowest = getLowestWeight();
                    ^
TestRenforthBoatRace.java:35: cannot find symbol
symbol  : variable redboat
location: class TestRenforthBoatRace
            array[0] = redboat.getSum();
                       ^
TestRenforthBoatRace.java:36: cannot find symbol
symbol  : variable greenboat
location: class TestRenforthBoatRace
            array[1] = greenboat.getSum();
                       ^
TestRenforthBoatRace.java:37: cannot find symbol
symbol  : variable yellowboat
location: class TestRenforthBoatRace
            array[2] = yellowboat.getSum();
                       ^
TestRenforthBoatRace.java:38: cannot find symbol
symbol  : variable blueboat
location: class TestRenforthBoatRace
            array[3] = blueboat.getSum();
                       ^
TestRenforthBoatRace.java:39: cannot find symbol
symbol  : variable orangeboat
location: class TestRenforthBoatRace
            array[4] = orangeboat.getSum();
                       ^
6 errors

any help would be appreciated guys. Thanks so much