Adding a Multiple Day for Multiple Items pricing is similar to adding a Multiple Day pricing.

From your Pricing tab, select Rent Type as Rent Item for multiple day for multiple items.
Since this is a multi-day for multiple items, you will have four options to work with and display on your front end: Hourly price, daily price, weekly price, and monthly price.

To rent your boat for multiple days, Enable Price Types by checking the check boxes of Daily Price, Hourly Price, Weekly Price, and Monthly Price, and define the amount as daily, hourly, weekly, and monthly.

Click the +Add More Items button to add more rental items of this rental type.

Again, define the amount as daily, hourly, weekly, and monthly for this new item.

You can add time from the Add New Time Slot.
Define your hour and minute and AM or PM for time from the drop down or you can add it by typing and then click Add Slot button.
Add as much time based on your rental service.

You can define a specific time and date for your rental item by toggling particular date time slots and add start date, end date and available time slots.

This is how it will look in your front end after configuring multi day multi item pricing.
