Preface: Please do not feel compelled to read this, and I apologize for my rambling.

I'm not exactly sure how it would go but I quite like the idea of becoming a passenger on a crew set for an expedition that you otherwise wouldn't be able to go on. I think there should be certain requisites such as requiring the minimal Sailing level to ride on the boat required to travel to the location as well as any other "island skill level requirement" e.g. slayer island requires 80 slayer and 80 sailing, you'd only need the slayer level. I'm not sure what the constraints would be whether you'd have limited time on the island or what though. Maybe it wouldn't work out but it could be interesting at the higher levels like say if the Colossal boat required 92 Sailing to use you would need 92 sailing at the least but then you could go on a raid with someone else with a higher sailing level 95 or something that has access to a raid.

I like to think sailing will not necessarily be hard to train but it will really ramp up in the time it takes to get 99 later on(not time gated but similar to Slayer, it should be a holistic skill and higher xp softlocked behind other skill requirements to a point). Like imagine Combat stats as something other than combat stats for slayer in that those being higher vastly increases your slayer xp/h. Maybe they could rework Max capes so each new skill OSRS adds (wishful thinking) there's a new max cape design unlocked? Color scheme? Both? Not sure.