Choose an unoccupied space within range that is either on the ground or upon the surface of water. At that point you conjure a water vehicle, determined by the level at which you cast this spell as detailed below (although you can use a higher level spell slot to summon a lower level's water vehicle if desired), if it would fit. If the water vehicle would not fit in the space then the spell fails and spell slot is wasted.

The water vehicle is conjured with all materials and items necessary for the function: such as oars, rope, nets, etc. For water vehicles that can attack with weapons there will be enough ammunition for 10 shots for each method of attack that uses consumable ammunition. A full crew is also conjured - the members will have a humanoid appearance but may otherwise appear as you choose - perhaps they will look human, or like zombies or skeletons? Regardless of the appearance given they will have the statistics of a Commoner but with the following differences:

• They will have proficiency in Water vehicles plus one skill or tool relevant for their function (navigator's tools for the navigator for example or cook's utensils for the cook, perception for the lookout or athletics for most others). 
• They have the amphibious trait and can breathe air and water.
• They have a swim speed equal to their walk speed.
• They will have the Fey creature type. They are actually fey spirits conjured into the current form.
• They do not need to eat, drink or sleep.
• If a conjured crew member is killed or drops to 0 hit points they disappear leaving no trace. They also disappear without trace if the spell ends.
• A crew member cannot attack any creature directly but can use the water vehicle's weapons (such as ballistas) if it has any. They can also use any offensive action if it does not cause any direct damage (such as grappling). 

Any conjured item or crew member will disappear if they are more than 300 feet from the water vehicle. If only part of an item is beyond the range that part vanishes but returns if the whole item is brought back within range - the same happens for crew members. If a crew member fully disappears as a result of this distance they immediately reappear in a random unoccupied space on the water vehicle.

The water vehicle lasts 1 day, if you cast this spell again you can create a new water vehicle or reset a current one. If you reset a current one the water vehicle is fully restored of any damage, the crew become a full crew with all hit points again and any missing items or objects that had been damaged or disappeared are fully returned plus the duration is reset back to 1 day. 

The vehicles you can conjure are as follows:

At base 3rd level you conjure a Rowboat.

At 4th level you conjure a Keelboat.

At 5th level you conjure a Longship.

At 6th level you conjure a Sailing Ship.

At 7th level you conjure a Warship.

At 8th level you conjure a Galley.