function(spec)
{
    // ------------------------------------------------------------------------
    var that = {};
    that.boat = spec === undefined ? 'Boat' : spec;

    var Appendage = "Boat.Centre.FrontFoil"; // Which appendage
    var ElementID = 1; // Which element of the appendage
    var iCPOpt = [0, 1, 2, 3, 4, 5, 6]; // Index of CPs you want to optimise

    // Could read existing foil parameters here and store for later use, e.g. for global scaling of chord

    // ------------------------------------------------------------------------
    // When model loads, set initial chord lengths according to the current chord definition 
    // ------------------------------------------------------------------------
    that.init = function (callType) {
        if (Host.foilHolder().foilDefinition("Boat.Centre.FrontFoil")) {
            // print("init " + callType);

            for (var i = 0; i < iCPOpt.length; i++) {
                var iCP = iCPOpt[i];
                var input = B("Boat.Centre.ChordCP" + i);
                if (input != null) {

                    var initChord = Host.foilHolder().foilDefinition(Appendage).elementDefinition(ElementID).chordDefinition().CP(iCP);

                    B("Boat.Centre.ChordCP" + i).setValue(initChord); // These need to be a states, not JS functions
                }
            }
        };
    };

    // ------------------------------------------------------------------------
    // Update model with new chord values
    // ------------------------------------------------------------------------
    that.preUpdate = function(callType)
    {
        if (Host.foilHolder().foilDefinition("Boat.Centre.FrontFoil")) {
            // print("preUpdate " + callType);
            for (var i = 0; i < iCPOpt.length; i++) {
                var iCP = iCPOpt[i];
                var input = B("Boat.Centre.ChordCP" + i); // These need to be states, not JS functions

                if (input != null) {
                    var CPy = input.outputValue();
                    Host.foilHolder().foilDefinition(Appendage).elementDefinition(ElementID).chordDefinition().setCPy(iCP, 0, CPy);
                }
            }
            B(Appendage).updateFoilFromDefinition(Host.foilHolder().foilDefinition(Appendage), false)
            
            // // Update structural properties at all time steps of the optimisation (not after a manual change)
            // if (callType != G.CallTypes.MANUAL_INIT_MAJOR) {
            //     Host.foilHolder().foilDefinition(Appendage).elementDefinition(ElementID).xnSCDefinition().estimate();
            //     Host.foilHolder().foilDefinition(Appendage).elementDefinition(ElementID).ynSCDefinition().estimate();
            //     Host.foilHolder().foilDefinition(Appendage).elementDefinition(ElementID).EIDefinition().estimate();
            //     Host.foilHolder().foilDefinition(Appendage).elementDefinition(ElementID).GKDefinition().estimate();
            // }

            // Update structural properties only if optimisation is successful.
            if (callType == G.CallTypes.OPTIMISATION_SUCCESS) {
                // print("preUpdate " + callType);
                Host.foilHolder().foilDefinition(Appendage).elementDefinition(ElementID).xnSCDefinition().estimate();
                Host.foilHolder().foilDefinition(Appendage).elementDefinition(ElementID).ynSCDefinition().estimate();
                Host.foilHolder().foilDefinition(Appendage).elementDefinition(ElementID).EIDefinition().estimate();
                Host.foilHolder().foilDefinition(Appendage).elementDefinition(ElementID).GKDefinition().estimate();
            }
        }
        // Other foil access:
        // Host.foilHolder().foilDefinition(Appendage).elementDefinition(ElementID).rondureDefinition().setCP(iCP,x,y);
        // Host.foilHolder().foilDefinition(Appendage).elementDefinition(ElementID).twistDefinition().setCPy(iCP, 0, twist, false);    			
        // To see full list of available functions, use query() in Gomboc Commands window
        // e.g. query(Host.foilHolder().foilDefinition("Boat.Centre.FrontFoil").elementDefinition(0));
    };    
    return that;
};