Added "F" designation as this watch follows all criteria in adverts, page 8, image 19. Will update with more pics and info when watch arrives. In need of a lot of work to case, but watch is running. 1 fifth second gradations to dial register. Radium numbers and hands, red seconds hand.
EDIT:- Caseback will not come off, so looked further and the bezel is removable, as in pics. Could not take out stem as should come out in two parts, male and female, but won't. After letting mvmnt. drop partially out, I could see inside for info, and caseback reads, "BULOVA WATCH CO. SWISS, 53, 246166." L3 on mvmnt. BXW, 10 BUC, 17 jewels. Running smoothly and keeping very good time. Length lug tip to lug tip is 37mm. Width minus crown is 30mm. lug gape is 16mm.
EDIT:- Name change to "Seabee" as watch is on leather strap, as per 1953 ad.
In reply to The ad for the 'F' variant by FifthAvenueRes…
Ha! I refuse to go down that road, Mark.
EDIT:- Then again, if you look at image 22, page8, there is a Watertite "F" chrome plated, expansion band, 17 jewels, index no. 45 WN 546 T, and below it says "Similar 15 jewels, leather strap, index no. 45 WN 545 T. No change to the letter designation, only different index nos. This is for the same year as the ad mentioned above.
On the same ad is the "Duo-wind G", RGP case, S/S back, expansion band, index no. 45 WN 543T. Below that it says 45 WN 544 T "Watertite E", similar but S/S water-resistant case, leather strap, all luminous dial.
I put it that the letter designation after some, if not all, watch names is for the case and/or dial, not the band.
I don't think a 10BUC has "hacking". This 10BUC movement in not in our movement database (yet). Lisa lists the 10BUC occurring in 1954 w/ 17Jewels in her movement DB at http://www.watchophilia.com/general-information/bulova-movements/ Ranfft lists as occurring 1951 thru 1954, 17 jewels, but no mention of hacking (http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&&2uswk&Bulova_10BUC). If it hacks, and you can see the 10BUC on the movement, it's a mystery to me.