d） on satisfactory completion of the yacht‘s interior painting and insulation stages， substantial completion of the yacht’s interior furniture built off the yacht， and at the start of fit out， us$127，500 （one hundred and twenty seven thousand five hundred）
e） on satisfactory completion of the yacht‘s exterior painting stages， us$127，500 （one hundred and twenty seven thousand five hundred）。
f） on satisfactory installation of the yacht‘s engines， generators and main engine room systems， together with installation of the fly bridge structure， us$127，500 （one hundred and twenty seven thousand five hundred）。
g） on delivery and final acceptance of the yacht by the buyer us$85，000 （eighty five thousand）。
2） the builder shall， by not less than fourteen days notice in writing， advise the buyer of the date upon which each instalment of the contract price shall become payable.
（i） subject to the builder‘s compliance with the notice provisions of the foregoing paragraph， each of the said instalments shall become due and payable upon the appropriate instalment event， subject to receipt by the buyer of the builder’s invoice thereof， accompanied by a “stage certificate” issued by the builder certifying that the appropriate instalment event has taken place.
（ii） prior to each instalment event， the builder shall notify the buyer， in writing， of the amount of any reduction in， or addition to， the contract price， in accordance with the terms of this contract. the instalment due on the forthcoming instalment event shall be adjusted to take account of any such amendment to the contract price.
4） the amount of each instalment of the contract price shall be paid direct to aaa‘s yacht company limited， a/c number 0842-5094 at citibank hong kong， （routed via citibank ny， aba # 021000089， a/c citibank hk， chips uid 030339， swift code citihkhx） for the account of the builder within fourteen banking days of the due date for payment and if not so paid shall （without prejudice to any other rights of the builder in respect of non-payment） bear interest from the due date until payment at hk base rate plus 4%.
5） in the event of the builder issuing a stage certificate under （3） （i） and the buyer considering that the builder should not have issued the same because the instalment event shall not have been reached， or， if reached， that the work or materials executed or incorporated by the builder in the yacht was not in accordance with the requirements of this contract or in accordance with good engineering practice then the buyer may give a counter notice specifying the matters by reason whereof the buyer contends that the stage certificate should not have been issued， and thereupon if the parties do not agree then the matter shall be referred for resolution to an arbitrator to be agreed by the parties.