With a standard set up 18'r and a 75 hp motor it should remain very light being under the Ranger's towing capacity.
My 18'r is a different story with a 115 hp, double decking, 4 batteries, livewell, 24 gal belly tank and a 24v TM that weighs 90 Lbs.
Painting the inside bottom is a waste of material and a source for issues, as water stands on the paint it will blister and water will get under the paint. The proper prep work for painting the inside bottom would take many hours too.
Craig's list or FB market place seem to have the most Starcraft boats;
No way to know what your Islander is worth without knowing more about it. As you know by being in the forum, selling and prices is frowned upon and not something discussed here but rather in PMs.
What's worse than any noob scavenging info as easy as they can are the so called experienced guys who've the been there done that types who give out really bad information. Normally that info is a short cut with bad materials.
For instance, a question about motorwell transom drain tubes. I...
Welcome aboard,
Always best to include any info you have on the motor / drive (serial #s) to get proper information in return. Over the decades motors get replaced so guessing that it's the original 2.5L Mercruiser 120 could be wrong.
The Mercruiser section here has lots of knowledge but in...
Having used both epoxy sealers I can say that the slightly thicker Coat-it did NOT completely seal the keel section of the Seafarer. I can only surmise that it just wasn't thin enough to get down in the narrow gaps. It did work well on the seams because of the lip allowing it to fill in the seam...