Upper Deck
1 - Mainmast
2 - Light Ballista
3 - Companionway to Lower Deck
4 - Hatches to Cargo Hold
The only modifications I made to this deck were to narrow the steps from the main deck to the foredeck. On a ship, stairs wouldn't be 5 feet wide.
Lower Deck
1 - Mainmast
2 - Bridge and Spelljammer Helm
3 - Captain's Cabin
4 - Crew Cabins
5 - Movable Walls
6 - Galley and Mess
7 - Cargo Loading Hatch (overhead)
8 - Cargo Hold
I modified this deck a bit. Note the added companionway from the crew quarters into the hold area. I also added 2 movable bulkheads with doors in them to enlarge the crew quarters and add a galley and mess. These bulkheads are secured to the hull by the same cleats used to secure cargo. The added space reduces the hold capacity to about 3 tons. If more cargo space is needed, the bulkheads can be moved all the way aft, and secured to the aft bulkhead.
I designed this variation to conserve space. In a ship this small, nearly 200 square feet of wasted space comes out to a lot.
Cost: 6,500 gp, or about 2,000 gp to refit a standard Dragonfly.
Upper Deck
1 - Mainmast
2 - Light Ballista
3 - Companionway to Lower Deck
4 - Cargo Hatches
I lowered the foredeck, and raised the aft deck, and unified them. This saved almost 50 square feet. It also increased the hold size by raising it's ceiling.
Lower Deck
1 - Mainmast
2 - Bridge and Spelljamming Helm
3 - Captain's Cabin
4 - Crew Cabins
5 - Movable Bulkheads
6 - Galley and Mess
7 - Cargo Hatch
8 - Cargo Hold
I modified this deck a lot. I decided to lose the rounded back of the main cabin area, and keep the movable bulkheads I used above. By doing this, and eliminating the companionway on the lower deck, I reclaimed about 150 square feet of space. This adds to the captain's and crew's cabins without taking any more space away elsewhere.
I had fun with this one... The yacht is the epitome of opulence, with its spacious cabins and expensive furnishings.
Cost: 75,000 to 150,000 gp and up. Don't bother trying to refit an existing hull, it costs about the same.
Upper Deck
1 - Mainmast
2 - Skylight
3 - Stairs to lower deck
4 - Skylight/Hatch
In the yacht configuration, there are no weapons.
Lower Deck
1 - Mainmast
2 - Common Room
3 - Main Stateroom
4 - Guest Stateroom
5 - Spelljamming Helm and Pilot and Crew Quarters
6 - Galley
7 - Skylight
8 - Grand Salon
In this configuration, the lower deck has also been unified. The skylight/hatch opens to load galley supplies, or change the helm. The hull, with both unified decks can be purchased without interior bulkheads for about 6,000 gp.