Need 'Roll & Tip' tips

[65Bowrider]

I am painting a bowrider and having some difficulties getting a nice finish and would like some help.

Located in So. Florida, boat is inside a hanger, using Interlux paint, rolling & tipping, using a foam roller & foam brush. The topsides & bottom turned out great, using some of the recommended 333 brushing fluid to thin the paint (2 oz). Instructions say 3oz / qt is max.

Now painting the sides of the outside hull (a vertical surface). And now I'm having problems.

With two oz of 333 thinner, it appeared as though the paint was trying to run...with horizontal waves running the length of the boat. Last coat backed down to only 1 oz thinner, and now it shows the brush strokes! So, is the paint drying too fast? or too slow??

The boat has 4 coats of red & still needs more coats for good coverage, so we're putting the paint on thin.... maybe too thin?

Also, when you tip, how much pressure do you put on the foam brush? Do you just barely touch to smooth out the bubbles from the roller ? or do you put enough pressure to glide thru the layer of fresh paint? Should you 'brush' more than once on an area? Rolling vertical, brushing horizontal from dry area to freshly painted area.

Any helpful hints will be tremendously appreciated.