Sea Hunt
I remember the TV series fondly, and the comic seems to capture the feel of the original. I like the art, it's clean but appealing, and I see the artist went to some trouble to render Lloyd Bridges' eyebrows very accurately. It's a small point, but it helps bring the character to life. The colouring is pleasing too, particularly in Treasure of the Mayas, the underwater scenes come across as beautifully fluid.
The Fisherman's Feat is a pleasantly amusing filler, but I found Underwater City slightly less gripping than the lead story, perhaps because of the scene in which it's set. There's less happening, too - they call Mike Nelson, he takes a dangerous job, has a setback, then goes on to save the day. Still, I suppose not having the adventure at sea does provide variety.
Overall I enjoyed this quite a lot, and it brought back some good childhood memories. Thanks for posting this one.
Sunken Gold
I'm less enamoured with this, for a couple of reasons. Firstly, the detectoscope - "You tune it in to what you're looking for, and it tells you how deep it is?" It reads like the same kind of pseudo-science that I'd probably tolerate in sci-fi, but it seems out of place here. Surely Charteris could've done better.
The art is by John Spranger who was apparently very highly thought of, and worked with Jack Cole and Will Eisner. I'm sure I remember seeing his name in a few early Marvel comics too. Anyway, as suspected this is a newspaper strip, cut down to fit the SDL format, and as a result the amount of detail in a panel seems to vary wildly, and it doesn't do Springer any favours. Clegg is a little disappointing too, he seems to be straight out of Villains R Us, the powerful build, scowling simian face, and stripey shirt are all dead giveaways. I'm sure it was better in newspaper form, and maybe in colour, there are some nice examples here:
https://www.lambiek.net/artists/s/spranger_john.htmSome interesting reading, QQ, I'll go back to Bold Venture for another listen before I comment.