If you are crazy enough to want to go from nautical level 48 to 49 by getting 20 exp at a time in Skull Island, why not?
I'm nautical level 35 and main level 35. Most ships that I can get to give me ONE nautical experience. At max, I'm looking at 25 to 50 and can't find any better ships to fight.
What exactly is the point to making it this way? Maybe have Skull Island ships give 1 exp but let the rest of the ships be set at a static rate. This will keep Skull Island clear of jam ups and still let people more easily level their nautical side as they level their character.
Because pzannucci , as you level up and get stronger (your character and your ship), your enemies become weaker and easier to defeat them so you will get less Nautical Experience. If you want to get more Nautical Experience and your character is level 50 as I understand, go to MS (Mooshu) there you will find more ships to battle that give you Nautical Experience of around 245 - 285. The lower the area you are at Nautical level 35 your ship is, the less Nautical Experience you will get. But just to warn you , MS ships are better fighters than you, so be careful and be prepared if you have good nautical strategies you will win them easy .
I try to keep my nautical the same level as my game level. Once the nautical I receive hits a certain amount or below, then I wait until I get to the next area, where the better ships are and work on my nautical again.
Mooshu ships are the top ones (at this time until a new world comes out). The top ships there are the Jade Fleet, which are level 48-50.
I have taken many lower level friends there to gain nautical (top amount is 285 nautical).
If you have someone that can take you to a higher level, great! If not, the best advice is to wait to battle ships for nautical until you get to the next area, where the ships will be better.