This post solidifies some ideas that I've had bouncing around in my head about a process for PCs recruiting sailors.
Recruiting a Crew
Whether it happens because of encountering natural hazards, losses in combat, acquiring a larger vessel or other reasons, it is inevitable that a captain at some point will need to hire new crew members. When that time comes, the Pathfinder core rulebook contains a valuable tool for adjudicating that effort: its description of the reincarnation spell.
More specifically, the table on page 332 provides a means of determining the species of those sailors in port who are looking to hire on with a new vessel. The GM should roll on that table, and then consult the chart below to determine just how many sailors of that race are present and available for hiring.
% Chance / # Available
1 / 1d4
4 / 1d6
10 / 1d8
12 / 1d10
15 / 1d12
Note that the PCs may always continue seeking available candidates with additional rolls on the chart, but each roll after the first decreases the number of characters available by one die type. After all, passing up on the more prominent candidates means that they might need to accept whomever they can find.
For example, Captain Horace and the crew of the Skylark pay a visit to the Crossroads asteroid colony; while there, they stop in at the Sign of the Ourobouros and look for new crew members. When they do so, the GM or a player rolls percentile, resulting in 70. Given that, the next roll is 1d10, with a result of 4. Thus, the PCs find four halfling sailors who are looking to sign on with a crew. While they could undertake negotiations to hire those NPCs, they might seek other candidates to supplement or replace the first group.
In that case, the GM or player should roll again. This time, the percentile result is 01, which would normally yield 1d4 bugbear candidates, but that is reduced by a step to nothing, and thus yields no candidates. Eventually, of course, this means that the PCs could run through any chances of finding potential crew members at a given location, and thus must go somewhere else in order to find new candidates. At the GM's discretion, that failure could mean that the PCs receive no more attempts in that location. As always, the GM can adjudicate unusual circumstances, such as if the PCs make successful Diplomacy checks, offer large signing bonuses for recruitment or the like. Note, too, that the GM should feel free to substitute other races depending on the particular location in which they're doing the recruiting.
First Impressions and Negotiations
Recruitment also provides a good opportunity for roleplaying, as the PCs meet potential new recruits; feel out their personalities; discuss and determine shares and accommodations; and the like. At the GM's discretion, this could also involve a Diplomacy check to determine the first impression that the PCs make on these recruits, and might even have long-term implications regarding those sailors' loyalty to the captain and other crew members.
To determine the difficulty of making a good first impression, compare the alignment of the new sailor(s) with that of the captain. Each step of difference between the two, decreases the starting attitude of the sailors one step from Helpful (and thus increases the base DC of the Diplomacy check by 5). Success on that check means that the captain has made a good impression, and thus they are more likely to remain loyal during difficult times; failure, on the other hand, could lead to dissent, factions and possibly even mutiny. Here again, the GM should apply bonuses or penalties to this check based on good or bad roleplaying or reasoning, or due to other factors.
Presented below is a base stat block for NPC sailors; the GM need only apply ability score modifiers and add special abilities based on the characters' race.
Various expert 1
N medium humanoid
Init +1; Senses Perception +5
AC 11, touch 11, flat-footed 10 (+1 Dex)
hp 8 (1d8)
Fort +0, Ref +1, Will +3
Spd 30 ft.
Melee Dagger +0 (1d4)
Ranged Dagger +1 (1d4)
Special Attacks None
Str 11, Dex 13, Con 10, Int 9, Wis 12, Cha 8
Base Atk +0; CMB +0; CMD 11
Feats Skill Focus (Profession: sailor)
Skills Climb +4, Knowledge (nature) +3, Perception +5, Profession (sailor) +8, Survival +5
Combat Gear Clothing, knife, miscellaneous personal possessions
Adding Some Personality
Finally, Table 4-4 on pages 95-6 of the GameMastery Guide can be a helpful tool for bringing this new batch of crew members to life, providing an inkling for their general disposition.
Continuing the previous example, the GM rolls an 90 on the aforementioned table. For that reason, the four halfling sailors come from a different culture, and thus frequently ask for explanation of seemingly mundane activities. Note, too, that the GM may wish to keep the result of this check secret, thus allowing for surprising drama at some point in the future.